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- <html>
- <head><title>Aging Eyes, Infant Eyes, and Excitable Tissues</title></head>
- <body>
- <h1>
- Aging Eyes, Infant Eyes, and Excitable Tissues
- </h1>
-
- <em>
- <p>
- The eyes and the lungs are sensitive tissues that are easily harmed by inappropriate environmental
- exposure. They are especially sensitive in infancy and old age.
- </p>
- <p>
- For 60 years there have been controversies about the cause of retinopathy of prematurity, which has
- blinded tens of thousands of people.
- </p>
- <p>
- Degeneration of the retina is the main cause of blindness in old people. Retinal injury is caused by
- ordinary light, when the eyes are sensitized by melatonin, prolactin, and polyunsaturated fats. Bright
- light isn't harmful to the retina, even when it is continuous, if the retina isn't sensitized.
- </p>
-
- <p>
- Melatonin and prolactin are induced by stress, and darkness is a stress because it impairs mitochondrial
- energy production.
- </p>
- <p>
- The polyunsaturated fats which accumulate in the brain and retina damage mitochondria.
- </p>
- <p>
- Iron, which accumulates prenatally, and then again with aging, reacts with unsaturated fats during
- stress to destroy cells.
- </p>
- <p>
- The popular supplements melatonin, tryptophan, fish oils, St. John's wort, and the various omega -3
- oils, all increase the risk of retinal light damage and macular degeneration. Serotonin uptake
- inhibiting antidepressants are suspected to be able to cause it.
- </p>
- <p>
- Processes similar to those that damage the over-sensitized retina can occur in other cells, as a result
- of stress. The substances that sensitize the retina to light-damage, can also increase the incidence of
- new or metastatic cancers.
- </p>
-
- <p>
- Iron supplements and the use of supplemental oxygen, especially with a vitamin E deficiency exacerbated
- by excessive unsaturated fats in the diet, are still commonly used exactly when they can do the most
- damage.
- </p></em>
- <hr />
-
- <p>
- One of the recognized achievements of biology has been the demonstration of life"s universality, in the
- sense that organisms of all sorts use the same fundamental genetic code, and that yeasts, lizards, apes, and
- people have remarkably similar cellular systems, as well as a great amount of genetic similarity.
- </p>
-
- <p>
- There has been another, less well recognized, sort of convergence going on in physiology and
- pathophysiology. Hans Selye"s concept of stress, "the syndrome of being sick," Otto Warburg"s argument that
- a "respiratory defect" was behind all kinds of cancer, and the idea of free radical damage as a common
- factor in disease and aging, helped to create a more general way of looking at the nature of disease that
- superceded medicine"s theories of disease pathogens and genetic mutations, which created thousands of
- "disease entities," none of which had much to do with the individuality of the patient or his environment.
- </p>
- <p>
- The understanding that plants and animals have much biochemistry in common has gradually changed the
- assumptions of the science establishment, which until recently insisted that only "ionizing radiation" could
- affect animals or other organisms that lacked chlorophyll--and insisted that ionizing rays acted only on the
- DNA. Visible light, the textbooks said, was not "chemically active," and so couldn"t possibly affect
- animals" cells. In animals, coloration was seen mainly as decoration and disguise, rather than as a
- functional part of their biochemistry.
- </p>
- <p>
- (Chemically, the meaning of "a pigment" is that it"s a chemical which selectively absorbs radiation. <strong
- >Old observations such as Warburg"s, that visible light can restore the activity of the "respiratory
- pigments," showed without doubt that visible light is biochemically active.
- </strong>By the 1960s, several studies had been published showing the inhibition of respiratory enzymes by
- blue light, and their activation by red light. The problem to be explained is why the science culture simply
- couldn"t accept crucial facts of that sort.)
- </p>
- <p>
- The retina, of course, was allowed (in the views of mainline science) to respond to ordinary light, but the
- few people who studied the biological effects of seasonal or daily cycles of light have until recently
- stayed very close to the nerve pathways leading from the retina to the pineal gland, because those pathways
- could be described in terms of an evolutionarily specialized "third eye." Even with a doctrine of a
- genetically specialized link between the retina and a little of the animal"s physiological chemistry, the
- great, slow-witted science establishment has done its best to avoid thoughts of any deep interaction between
- an organism and its environment, by insisting that the organism runs according to a genetically determined
- "clock" which is located in a few cells in a certain area of the brain, and that nervous impulses from the
- retina have only the small privilege of "setting the clock."
- </p>
- <p>
- It didn"t matter to the academic and medical worlds that a professor, Frank A. Brown, had long ago disproved
- the idea of an innate genetic "clock," because philosophy is much stronger than evidence. Leibniz had said
- that everything in the world runs on its own inner clock, without needing to perceive its surroundings, and
- this idea that everything in the world is a "windowless monad" resonated through the world of science,
- because it justified the pompous authoritarian attitudes of the experts who knew that anything that wasn"t
- already in their heads couldn"t be considered knowledge. <strong>If an organism"s "essence is contained in
- its genes," then it clearly doesn"t interact in any meaningful way with most of its environment.</strong
- > This is the sort of culture that imbued research on the biology of light cycles.
- </p>
-
- <p>
- When I moved from Mexico, first to Montana and then to Oregon in 1966, I became very conscious of how light
- affects the hormones and the health. (For example, in Montana I experienced an interesting springtime
- shedding of body hair.) Many people who came to cloudy Eugene to study, and who often lived in cheap
- basement apartments, would develop chronic health problems within a few months. Women who had been healthy
- when they arrived would often develop premenstrual syndrome or arthritis or colitis during their first
- winter in Eugene.
- </p>
- <p>
- The absence of bright light would create a progesterone deficiency, and would leave estrogen and prolactin
- unopposed. Beginning in 1966, I started calling the syndrome "winter sickness," but over the next few years,
- because of the prominence of the premenstrual syndrome and fertility problems in these seasonally
- exacerbated disorders, I began calling it the pathology of estrogen dominance. In the endocrinology classes
- I taught at the National College of Naturopathic Medicine, I emphasized the importance of light, and
- suggested that medicine could be reorganized around these estrogen-related processes. If the sparrows of
- Times Square mated in the winter because of the bright lights, it seemed clear that bright artificial light
- would be helpful in regulating human hormones.
- </p>
- <p>
- In our lab at the University of Oregon, our hamsters would try to hibernate, even though they were in
- temperature-controlled laboratories with regular cycles of artificial light. (The ceiling lights provided
- only dim illumination inside their cage boxes, so they were probably in a chronic state of light
- deprivation, which probably increased their sensitivity to the weak environmental cues that Frank Brown had
- investigated, possibly microwaves that easily penetrated the lab walls.) During the winter, when they were
- infertile, I found that their thymus glands practically disappeared. The mechanism seemed to include the
- increase of pineal gland activity (probably increasing melatonin synthesis) in the winter, under the
- intensified activity of the "sympathetic nervous system" (with increased activity of adrenalin and other
- catecholamines), and the melatonin was apparently a signal for suppressing fertility during the stressful
- winter. In some animals (Shvareva and Nevretdinova, 1989), estrogen is increased during hibernation,
- contributing to the reduction of body temperature.
- </p>
- <p>
- In 1994 A.V. Sirotkin found that melatonin inhibits progesterone production but stimulates estrogen
- production, and it"s widely recognized that melatonin generally inhibits the thyroid hormones, creating an
- environment in which fertilization, implantation, and development of the embryo are not possible. This
- combination of high estrogen with low progesterone and low thyroid decreases the resistance of the organism,
- predisposing it to seizures and excitotoxic damage, and causing the thymus gland to atrophy.
- </p>
- <p>
- Cyclical exposure to melatonin can have an effect on the reproductive system opposite to that of chronic
- exposure, and the way exogenous melatonin is delivered to the animal can have unexpected effects on the
- actual amount of melatonin circulating in the blood (Wright and Alves, 2001). The actual amount of melatonin
- in the tissues, its relation to the normal cycling of the animal, and the influence of temperature, are
- often disregarded in melatonin research, making it hard to interpret many of the publications.
- </p>
- <p>
- There is a lot of talk about melatonin"s function as an antioxidant, but, like so many other "antioxidants,"
- melatonin can act as a pro-oxidant at physiologically relevant concentrations<strong>;</strong> some studies
- have found that it, like estrogen, increases the activity of the pro-oxidative free radical nitric oxide
- (which acts like melatonin on pigment cells, causing them to lighten). The promoters of estrogen are also
- making claims that estrogen is a protective antioxidant, though that isn"t true of physiological
- concentrations of estrogen, which can catalyze intense oxidations. The market culture seems to guide most
- research in these substances.
- </p>
-
- <p>
- Almost any kind of stress increases the formation of melatonin.
- </p>
- <p>
- In some animals, melatonin has been shown to be responsible for whitening of the hair during the winter. In
- some species it acts directly on the pigment cells, but in other species it seems to inhibit the action of
- the melanocyte stimulating hormone.
- </p>
- <p>
- In snowy climates, it"s "ecologically" rational for animals to turn white in the winter, for camouflage. But
- tadpoles also turn white in the dark, or under the influence of melatonin, and the biological meaning of
- that isn"t so clear. It"s possible that being white would reduce their loss of heat through radiation, but I
- think it is more likely that it relates to an increased ability of weak radiation to penetrate their
- tissues, rather than being stopped near the surface by the melanin in the skin. The absence of melanin makes
- them more sensitive to light. Bright light suppresses their melatonin, and makes them turn dark brown or
- black, and this protects them from bright sunlight.
- </p>
- <p>
- In the retina, melatonin increases the sensitivity of the cells to dim light. It, along with prolactin,
- another nocturnal hormone, helps to produce dark adaptation of the eyes.
- </p>
- <p>
- Melatonin increases the concentration of free fatty acids during the night (John, et al., 1983; John and
- George, 1976)), so it"s interesting that one of the long-chain highly unsaturated fatty acids, DHA
- (docosahexaenoic acid), also increases the light sensitivity of the retina.
- </p>
- <p>
- Melatonin lowers body temperature, causes vasoconstriction in the brain, heart, and other organs, and slows
- reactions. An antagonist to melatonin acts as an antidepressant, reducing "behavioral despair" resulting
- from stress. (Dubocovich, et al., 1990.) So, in the behavioral sense, melatonin reduces sensitivity, yet it
- increases the eyes" sensitivity to light, causing them to be injured by light that would otherwise be
- harmless.
- </p>
-
- <p>
- Since a hibernating animal under the influence of melatonin can become very cold, the light-sensitizing
- function of melatonin is probably related to the biological need to be roused out of the torpor
- occasionally. (Hibernators apparently have to warm up occasionally to sleep in the ordinary manner.)
- Melatonin is said to intensify dreaming, which is part of the process of arousal from sleep.
- </p>
- <p>
- All of the stress-related hormones increase during the night. One of the ways these hormones of darkness act
- is to increase the sensitivity to light, in a process that is an important adaptation for organisms in dim
- light. In the night, our ability to see (and respond to) dim light is increased. But dark-adapted eyes are
- very sensitive to injury by bright light. Light that ordinarily wouldn"t harm the eyes, will do serious
- damage when the eyes are dark adapted.
- </p>
- <p>
- In thinking about the effects of stress and oxygen deprivation, I read the studies demonstrating that the
- formation of the oxygen-wasting age pigment, lipofuscin, is increased by estrogen, by oxygen deprivation (in
- carp living below the ice, or even in fetuses), by metals such as iron, by x-rays, and by highly unsaturated
- fats.
- </p>
- <p>
- Free fatty acids that are mobilized from storage tissues in the night and in the winter also tend to
- increase with aging, as the ability to tolerate stress decreases. Poor circulation and lipofuscin tend to be
- associated, in a vicious cycle. This means that the retina becomes easier to injure by light in old age, for
- some of the same reasons that the infant"s retina is susceptible.
- </p>
- <p>
- The fetus accumulates a very large amount of iron, and it absorbs melatonin from the maternal circulation.
- Prolactin is sometimes elevated in the newborn. Premature babies are often given extra oxygen, which tends
- to cause vasoconstriction by displacing carbon dioxide. Melatonin"s ability to cause vasoconstriction means
- that stress makes supplemental oxygen more toxic. Synthetic glucocorticoids are often given to premature
- babies, adding to the risk of retinal damage.
- </p>
- <p>
- When the mother has been given iron supplements during pregnancy, along with unsaturated oils in the diet,
- the baby is likely to be born with a vitamin E deficiency and suppressed thyroid function, increasing the
- probability that it will be jaundiced, leading to treatment of the jaundice with exposure to very bright
- light.
- </p>
-
- <p>
- Although Yandell Henderson had already, in 1928, explained the need for carbon dioxide to be used with
- oxygen for resuscitating infants or adults, medical researchers and hospital workers could never accept the
- idea, probably because of a fundamental misunderstanding of the Henderson-Hasselbalch equation. Animal
- experiments show that supplemental oxygen, without carbon dioxide, causes vasoconstriction, reducing the
- tissues" supply of glucose as well as oxygen. In combination with too much light, especially blue light, it
- damages the retina. At hyperbaric pressure, oxygen causes seizures, as well as damage to the lungs and other
- tissues.
- </p>
- <p>
- The contribution of bright light to retinal damage in babies has been denied in several recent publications,
- and these articles undoubtedly provide useful material for defense lawyers to use when hospitals are sued
- for causing blindness. One publication based on experiments with kittens concludes that bright light does
- not harm the newborn"s retina, but the comparison is between continuous light and intermittent light, rather
- than between bright light and dim light. Twelve hours of total darkness, rather than sparing the eye by
- reducing its exposure to light, would sensitize the eye. The only reason such appalling things can be
- published is that their conclusions protect the hospitals.
- </p>
- <p>
- A few good studies of the effect of bright light on the retina, and the fact that dark-skinned people with
- more protective pigment in their eyes have a lower incidence of retinopathy of prematurity, make it clear
- that the ordinary laws of physics and chemistry actually do apply to the infant eye.
- </p>
- <p>
- Light and stress, especially with excess iron, damage the retina when the cells contain too much PUFA, since
- these fats react with light and free radicals. The nocturnal/stress hormones, especially prolactin and
- melatonin, make the retina more sensitive to light, and more easily damaged. (It's too much darkness that
- sets up the problem, since the eyes will adapt to excess light, but darkness increases their sensitivity.)
- </p>
- <p>
- The use of lasers to operate on eyes produces intense inflammation of the eye, but even at low dose the
- diffusing light causes retinal/macular damage.
- </p>
- <p>
- Cytochrome oxidase is one of the enzymes damaged by stress and by blue light, and activated or restored by
- red light, thyroid, and progesterone. It's a copper enzyme, so it's likely to be damaged by excess iron. It
- is most active when it is associated with a mitochondrial lipid, cardiolipin, that contains saturated
- palmitic acid<strong>;</strong> the substitution of polyunsaturated fats lowers its activity. Mitochonrial
- function in general is poisoned by the unsaturated fats, especially arachidonic acid and DHA.
- </p>
-
- <p>
- Creating a "deficiency" of DHA, even when an oil of known toxicity is used to replace the omega -3 oils,
- prevents retinal damage from light. Despite evidence of this sort, Mead Johnson is going ahead with the
- marketing of its baby formula containing added DHA which is industrially extracted from algae. (Although the
- researchers who claim that DHA is beneficial haven"t answered my letters, a representative of the company
- that manufactures it did answer my question about the actual composition of the oil, and acknowledged that
- they don"t have any idea what the minor ingredients might be.)
- </p>
- <p>
- When animals are made "deficient" in all the exogenous polyunsaturated fatty acids, linoleic and arachidonic
- acid as well as linolenic and DHA, they become remarkably resistant to all sorts of stress and toxins.
- </p>
- <p>
- The polyunsaturated fats make the lungs more sensitive to excess oxygen or hyperventilation, they make the
- eyes more sensitive to light, and they make the brain more sensitive to fatigue.
- </p>
- <p>
- The use of synthetic glucocorticoid hormone is standard in treating very premature babies, although it is
- known to contribute to eye damage. This is because it is considered necessary to improve the lung function
- of premature babies with respiratory distress. But there is no clear evidence that it is beneficial for lung
- function in the long run, and very clear evidence that it damages the brain and other organs. There is
- widespread agreement regarding the use of the glucocorticoids <strong><em>
- prenatally</em></strong> to accelerate lung development in women who seem likely to deliver
- prematurely. Natural cortisol is a factor that promotes lung development prenatally. But cortisol is also a
- signal produced by a stressed fetus, that triggers the birth process. Cortisol, or the synthetic
- glucocorticoid, inhibits progesterone production, and stimulates estrogen production, activating uterine
- contractions and other processes that terminate the pregnancy.
- </p>
- <p>
- Apparently, it doesn"t occur to many people that administering the glucocorticoid triggers premature birth,
- creating the problem they are intending to treat.
- </p>
-
- <p>
- Recognizing causal connections between premature birth and respiratory distress and retinopathy of
- prematurity, it would be obvious that the greatest effort should be made to prevent the problems by
- improving the health of pregnant women. Hospitals, however, are invested in high technology systems for
- treating these problems, and even though their results are dismal, they can"t make money by getting pregnant
- women to eat enough protein to prevent preeclampsia, which is a major cause of premature birth, or by
- treating the problems with salt, magnesium, progesterone, thyroid, and aspirin when the women haven"t had a
- good diet.
- </p>
- <p>
- Historically, preeclampsia has been blamed on the mother"s or fetus"s "bad genes," and that cultural bias
- was the setting in which these high technology prenatal and neonatal systems developed. High technology
- "neonatology" derives from the same ideology that motivated Josef Mengele"s genetic research in Auschwitz.
- The idea of genetic determination is still motivating resistance to reasonable preventive approaches.
- </p>
- <p>
- Thyroid, i.e., T3, is very effective in accelerating lung development in the fetus, and it doesn"t have any
- of the harmful effects of the synthetic glucocorticoids. It normalizes the hormones, increasing progesterone
- and decreasing estrogen, which are needed for full-term gestation, the opposite of the glucocorticoids"
- effects. While the cortisol-like drugs damage the brain and other organs, thyroid and progesterone protect
- them.
- </p>
- <p>
- <strong>Old organisms, like newborns, are easily injured by all sorts of inappropriate excitation. As in
- premature babies, the aged eyes, lungs, and brain are especially sensitive to damage by stress.<em>
- But all organs are subject to the same kinds of damage.
- </em></strong>
- Medical treatments for respiratory distress and macular degeneration in old people are often the same as
- those used so inappropriately for babies.<strong><em>
- The good health practices that can prevent the inflammatory and degenerative diseases can often make
- it possible for damaged tissues to recover, even in old age.</em></strong>
- </p>
-
- <p>
- The pituitary hormones, especially prolactin and TSH, are pro-inflammatory, and darkness increases TSH along
- with prolactin, so to compensate for a light deficiency, the pituitary should be well-suppressed by adequate
- thyroid. Armour thyroid or Thyrolar or Cynoplus, Cytomel, would probably be helpful. (Eye-drops containing
- T3 might be a way to restore metabolic activity more quickly.) Limiting water intake (or using salt
- generously) helps to inhibit prolactin secretion. The saturated fats protect against the body's stored PUFA,
- and keeping the blood sugar up keeps the stored fats from being mobilized. Aspirin (or indomethacin) is
- generally protective to the retina, analogously to its protection against sunburn. Adequate vitamin E is
- extremely important. There are several prescription drugs that protect against serotonin excess, but thyroid
- and gelatin (or glycine, as in magnesium glycinate) are protective against the serotonin and melatonin
- toxicities. Copper and magnesium deficiencies predispose to retinal damage. Red light is protective, blue
- light (or u.v.) is harmful, so wearing orange lenses would be helpful. Progesterone and pregnenolone, by
- reducing the stress reactions, should be helpful--in the eye diseases of infancy and old age, as they are in
- the respiratory distress syndromes.
- </p>
- <p><strong><h3>REFERENCES</h3></strong></p>
- <p>
- Eksp Klin Farmakol 1999 Mar-Apr; 62(2):58-60.<strong>
- [Melatonin lowers the threshold of light sensitivity of the human retina]</strong>
- ; Arushanian EB, Ovanesov KB. Department of Pharmacology, Stavropol State Medical Academy, Russia. After
- chronic use of melatonin (3 mg before night-time for 14 days) campimetry showed a significant decrease of
- the threshold of brilliance sensitiveness of the retina in the absence of authentic changes of the
- sensorimotor response latency in individuals of the older age group. A connection between the eye light
- sensitivity and the direct effect of the hormone on the photoreceptors is suggested.
- </p>
- <p>
- Cochrane Database Syst Rev 2001;4:CD001077. <strong>Restricted versus liberal oxygen exposure for preventing
- morbidity and mortality in preterm or low birth weight infants</strong> (Cochrane Review). Askie LM,
- Henderson-Smart DJ.
- </p>
- <p>
- Prog Clin Biol Res 1989;312:95-112. <strong>The metabolism of omega-3 polyunsaturated fatty acids in the
- eye: the possible role of docosahexaenoic acid and docosanoids in retinal physiology and ocular
- pathology.</strong> Bazan NG.
- </p>
- <p>
- Biull Eksp Biol Med 1976 Oct;82(10):1181-3. <strong>[Role of the biological activity of serotonin in the
- production of the "shock lung" syndrome.] ;</strong> Bazarevich GI, Deviataev AM, Likhtenshtein AO,
- Natsvlishvili BP, Sadeko MK.
- </p>
- <p>
- Invest Ophthalmol Vis Sci 1993 Sep;34(10):2878-80. <strong>
- An elevated hematogenous photosensitizer in the preterm neonate.</strong> Bynoe LA, Gottsch JD, Sadda
- SR, Panton RW, Haller EM, Gleason CA.
- </p>
- <p>
- Eur J Endocrinol 1995 Dec;133(6):691-5. <strong>Melatonin enhances cortisol levels in aged but not young
- women.</strong> Cagnacci A, Soldani R, Yen SS
- </p>
-
- <p>
- Am J Psychiatry 1976 Oct;133(10):1181-6. <strong>Negative effects of melatonin on depression.</strong>
- Carman JS, Post RM, Buswell R, Goodwin FK. In order to test the efficacy of the pineal neurohumor melatonin
- on depression, the hormone was administered in varying doses to six moderately to severely depressed
- patients and two patients with Huntington's chorea in double-blind crossover study. <strong>Melatonin
- exacerbated symptoms of dysphoria in these patients, as well as causing a loss of sleep and weight and a
- drop in oral temperature. Melatonin increased cerebrospinal fluid 5-hydroxyindoleacetic acid and
- calcium</strong> in three of four patients studied. The authors discuss the implications of this
- finding.
- </p>
- <p>
- Neuroendocrinol Lett 2001 Dec;22(6):432-4. <strong>Melatonin shortens the survival rate of Ehrlich
- ascites-inoculated mice.</strong> Catrina SB, Curca E, Catrina AI, Radu C, Coculescu M. Dept.
- Endocrinology II, University of Medicine and Pharmacy Carol Davila, Bucharest, Romania. <a
- href="mailto:sergiu-bogdan.catrina@molmed.ki.se"
- target="_blank"
- >sergiu-bogdan.catrina@molmed.ki.se</a>
- <hr />
- </p>
- <p>
- J Neurochem 1988 Apr;50(4):1185-93. <strong>Induction of intracellular superoxide radical formation by
- arachidonic acid and by polyunsaturated fatty acids in primary astrocytic cultures.</strong> Chan PH,
- Chen SF, Yu AC.
- </p>
- <p>
- Graefes Arch Clin Exp Ophthalmol 1993 Jul;231(7):416-23. <strong>Inhibition of cytochrome oxidase and
- blue-light damage in rat retina.</strong> Chen E. St. Erik's Eye Hospital, Karolinska Institute,
- Stockholm, Sweden.<strong>
- The activity of cytochrome oxidase, outer nuclear layer thickness, and edema were quantitatively
- evaluated in the blue-light exposed rat retina.</strong>
- Dark-adapted or cyclic-light reared rats were exposed to blue light with a retinal dose of 380 kJ/m2.
- Immediately, 1, 2, and 3 day(s) after exposure, the retinas of six rats from each adaptation group were
- examined. There was no difference between the dark-adapted and cyclic-light reared rats. Immediately after
- light exposure, cytochrome oxidase activity decreased. The activity in the inner segments remained low at
- day 1, while severe edema was observed in the inner and outer segments. The outer nuclear layer thickness
- decreased 1-3 days after exposure. The blue-light exposure inhibited cytochrome oxidase activity and caused
- retinal injury. Similarity of the injury process in the dark-adapted and cyclic-light reared retinas
- suggests that rhodopsin was not involved. The inhibition of cytochrome oxidase could be a cause of retinal
- damage.
- </p>
-
- <p>
- Acta Ophthalmol Suppl 1993;(208):1-50. <strong>Inhibition of enzymes by short-wave optical radiation and its
- effect on the retina.</strong> Chen E. Eye Laboratory, St. Erik's Eye Hospital, Stockholm, Sweden.
- "Exposure to short-wave optical radiation is a potential hazard for vision. In the present study, blue-light
- damage is studied in rat retina." <strong>"Blue light inhibited cytochrome
- </strong>
- <strong>oxidase</strong>
- at a retinal dose of about 110 kJ/m2. This inhibition was reversible, and is probably related to the light
- regulation of retinal metabolism. At a retinal dose of about 380 kJ/m2, the inhibition of cytochrome oxidase
- was followed consecutively by a probable redistribution of chlorine and potassium in the inner and outer
- segments, damage to the mitochondria in the inner segments, edema in the inner and outer segments, and
- progressive degeneration of photoreceptor cells. Dark adaptation did not increase the blue-light retinal
- injury. <strong>These findings support the hypothesis that inhibition of cytochrome oxidase is one of the
- causes of blue-light retinal damage.</strong>"
- </p>
- <p>
- Aust N Z J Ophthalmol 1997 May;25 Suppl 1:S73-5. <strong>Retinal control of scleral precursor
- synthesis.</strong> Devadas M, Morgan
- </p>
-
- <p>
- Eur J Pharmacol 1990 Jul 3;182(2):313-25. <strong>Antidepressant-like activity of the melatonin receptor
- antagonist, luzindole (N-0774), in the mouse behavioral despair test.</strong> Dubocovich ML, Mogilnicka
- E, Areso PM.
- </p>
- <p>
- J Pharmacol Exp Ther 1988 Sep;246(3):902-10. <strong>Luzindole (N-0774): a novel melatonin</strong>
- <strong>
- receptor antagonist.</strong> Dubocovich ML.
- </p>
- <p>
- Exp Eye Res 1985 Oct;41(4):497-507. <strong>The diurnal susceptibility of rat retinal photoreceptors to
- light-induced damage.</strong> Duncan TE, O'Steen WK. Exposure of albino rats to high intensity light
- results in rapid, graded loss of photoreceptors. The hormonal status and age of an animal at the time of
- exposure affect the severity of light-induced retinal damage. The adrenal axis and pituitary hormones
- (prolactin) have been demonstrated previously to affect the degree of cell death in the retina. Because
- circadian rhythms for adrenal and pituitary secretion have been demonstrated in the rat, a series of
- experiments was undertaken to determine if a diurnal pattern of retinal susceptibility to light damage
- exists which might be related to endogenous endocrine rhythms. Male Sprague-Dawley rats were exposed to 4 hr
- of high intensity fluorescent light for 8 consecutive days during different phases of the 14:10 hr light:
- dark animal room light cycle. Morphometric analysis performed at the light microscopic level 2 weeks after
- exposure demonstrated a differential susceptibility to light-induced cell death depending upon the period
- during the light-dark cycle when animals received their daily light exposure. Neuronal cell death was
- confined to the outer nuclear layer as previously described. <strong>The retinas of animals exposed during
- the middle of the dark period or during the first 5 hr of the light period were significantly more
- damaged than the retinas of animals exposed during the last 9 hr of the light period.</strong> Control
- groups for the relative amounts of dark-adaptation between groups suggested that the diurnal susceptibility
- to light damage was not solely dependent upon the degree of dark adaptation. These results demonstrate a
- diurnal susceptibility of photoreceptors to light-induced cell death.
- </p>
-
- <p>
- Nature 1983 Dec 22-1984 Jan 4;306(5945):782-4. <strong>Melatonin is a potent modulator of dopamine release
- in the retina.</strong> Dubocovich ML.
- </p>
- <p>
- Semin Perinatol 2000 Aug;24(4):291-8. <strong>Environmental light and the preterm infant.
- </strong>Fielder AR, Moseley MJ. The lighting environment of the preterm baby is quite unlike that
- experienced at any other time of life. Physical and physiological factors control how much light reaches the
- retina of the preterm baby. With respect to the former, although many neonatal intensive care units are
- brightly and continuously lit, there is a trend to employ lower levels of illumination and to introduce
- cycling regimens. Physiological determinants of the retinal light dose include: eyelid opening and
- transmission, pupil diameter and the transmission characteristics of the ocular media. Early exposure to
- light does not significantly hasten or retard normal visual development, and it is not a factor in the
- development of retinopathy of prematurity. However, ambient neonatal intensive care unit illumination may be
- implicated in some of the more subtle visual pathway sequelae that cannot be attributed to other major
- complications of preterm birth including altered visual functions and arrested eye growth.
- </p>
- <p>
- Pediatrics 1992 Apr;89(4 Pt 1):648-53. <strong>
- Light and retinopathy of prematurity: does retinal location offer a clue?</strong> Fielder AR, Robinson
- J, Shaw DE, Ng YK, Moseley MJ. Nursery illumination has been implicated in the pathogenesis of retinopathy
- of prematurity (ROP), although the results of recent studies are conflicting. The data base for this article
- is a prospective ROP study on 607 infants of birth weight less than or equal to 1700 g including 35 larger
- siblings from multiple births when 1 infant fulfilled the birth weight criteria. Retinopathy commences
- preferentially in the nasal retina of the most immature neonate and is less likely to develop, or its onset
- is delayed, in the superior and inferior<strong>
- regions. These findings cannot be fully accounted for by regional vascular and neuroanatomical
- variations. Radiometric and physiological evidence suggests that the very immature neonate, most at risk
- of developing severe ROP, receives the greatest retinal irradiance. Furthermore, ROP commences in the
- areas of the retina receiving the highest light dose, and its onset is either retarded or inhibited in
- the darker retinal regions. Further studies are required to</strong> determine whether early exposure to
- light is a factor in the development of ROP. If a causal relationship is proven, here at least is one
- modality that can easily and immediately be controlled.
- </p>
-
- <p>
- N Engl J Med 1985 Aug 15;313(7):401-4. <strong>Effect of bright light in the hospital nursery on the
- incidence of retinopathy of prematurity.</strong> Glass P, Avery GB, Subramanian KN, Keys MP, Sostek AM,
- Friendly DS. The preterm infant is subjected to prolonged exposure to ambient nursery illumination at levels
- that have been found to produce retinal damage in animals. We prospectively investigated the effect of
- exposure to light in two intensive care nurseries by comparing the incidence of retinopathy of prematurity
- among 74 infants from the standard bright nursery environment (median light level, 60 foot-candles [ftc])
- with the incidence among 154 infants of similar birth weight for whom the light levels were reduced (median,
- 25 ftc). <strong>There was a higher incidence of retinopathy of prematurity in the group of infants who had
- been exposed to the brighter nursery lights,</strong> particularly in those with birth weights below
- 1000 g (86 percent vs. 54 per cent, P less than 0.01 by chi-square test). We conclude that the high level of
- ambient illumination commonly found in the hospital nursery may be one factor contributing to retinopathy of
- prematurity and that safety standards with regard to current lighting practices should be reassessed.
- </p>
- <p>
- Doc Ophthalmol 1990 Mar;74(3):195-203. <strong>Light and the developing retina.
- </strong>Glass P. George Washington University School of Medicine & Health Sciences, Washington, DC.
- <strong>"Retinopathy of prematurity (ROP) has increased in the United States in the past decade.</strong>"
- </p>
-
- <p>
- Pediatr Res 1987 Oct;22(4):414-6. Calcemic responses to photic and pharmacologic manipulation of serum
- melatonin. Hakanson DO, Penny R, Bergstrom WH.
- </p>
- <p>
- Pediatr Res 1990 Jun;27(6):571-3. <strong>Pineal and adrenal effects on calcium homeostasis in the
- rat.</strong> Hakanson DO, Bergstrom WH.
- </p>
- <p>
- Science 1981 Nov 13;214(4522):807-9. <strong>Phototherapy-induced hypocalcemia in newborn rats: prevention
- by melatonin.</strong> Hakanson DO, Bergstrom WH.
- </p>
- <p>
- Doc Ophthalmol 1992;79(2):141-50. <strong>Diurnal variations in the electroretinographic c-wave and retinal
- melatonin content in rats with inherited retinal dystrophy.</strong> Hawlina M, Jenkins HG, Ikeda H.
- </p>
-
- <p>
- <strong>J.A.M.A. 90:353 (Feb. 25) 1928. The Prevention and Treatment of Asphyxia in the New-Born, Henderson,
- Yandell.</strong>
- </p>
- <p>
- Neuroendocrinology 2001 Feb;73(2):111-22. <strong>Estrogen modulates alpha(1)/beta-adrenoceptor- induced
- signaling and melatonin production in female rat pinealocytes.</strong> Hernandez-Diaz FJ, Sanchez JJ,
- Abreu P, Lopez-Coviella I, Tabares L, Prieto L, Alonso R.
- </p>
- <p>
- J Neurosci Res 1989 Oct;24(2):247-50. <strong>Brain mitochondrial swelling induced by arachidonic acid and
- other long chain free fatty acids.</strong> Hillered L, Chan PH.
- </p>
- <p>
- J Neurosci Res 1988;19(1):94-100. <strong>Effects of arachidonic acid on respiratory activities in isolated
- brain mitochondria.</strong>
-
- Hillered L, Chan PH.
- </p>
- <p>
- J Neurosci Res 1988 Aug;20(4):451-6. <strong>Role of arachidonic acid and other free fatty acids in
- mitochondrial dysfunction in brain ischemia.</strong> Hillered L, Chan PH.
- </p>
- <p>
- J Neurosci Res 1989 Oct;24(2):247-50. <strong>
- Brain mitochondrial swelling induced by arachidonic acid and other long chain free fatty acids.</strong>
- Hillered L, Chan PH.
- </p>
- <p>
- J Clin Epidemiol 1992 Nov;45(11):1265-87. <strong>Oxygen as a cause of blindness in premature infants:
- "autopsy" of a decade of errors in clinical epidemiologic research.</strong> Jacobson RM, Feinstein AR.
- Clinical Epidemiology Unit, Yale University School of Medicine, New Haven, CT 06510. "Several intellectual
- "autopsies" have recently reviewed errors in clinical epidemiologic studies of causation, such as the
- original claim that amyl nitrite "poppers" caused AIDS. The current autopsy was done to determine why it
- took<strong>
- more than a decade--1942 to 1954--to end an iatrogenic epidemic in which high-dose oxygen therapy led to
- retrolental fibroplasia (RLF) in premature infants, blinding about 10,000 of them.
- </strong>The autopsy revealed a museum of diverse intellectual pathology."
- </p>
-
- <p>
- Curr Eye Res 2001 Jul;23(1):11-9. <strong>Rod outer segments mediate mitochondrial DNA damage and apoptosis
- in human retinal pigment epithelium.
- </strong>
- Jin GF, Hurst JS, Godley BF.
- </p>
- <p>
- Endocrinol Exp 1976 Jun;10(2):131-7. <strong>Diurnal variation in the effect of melatonin on plasma and
- muscle free fatty acid levels in the pigeon.</strong>
- John TM, George JC. Pigeons maintained on standard diet and held under 12 h daily photo-period in a
- controlled environmental room, were given intravenous injections of melatonin. A low dose (1.25 mg/kg body
- weight) of melatonin when given in the middle of the<strong>
- scotophase, produced a significant increase in plasma FFA when estimated at 20 min and 90 min
- post-injection, whereas no significant change was seen with injections given in the middle of the
- photophase. No significant change in muscle FFA level was obtained either during the photophase or the
- scotophase</strong> when estimated at 90 min postinjection. With a higher dose (5 mg/kg body weight) of
- melatonin given in the scotophase, on the other hand, a significant increase<strong>
- in both plasma as well as muscle FFA levels was obtained at 90 min</strong> post-injection but there was
- no effect on plasma FFA at 20 min or 90 min post-injection in the photophase and at 20 min in the
- scotophase. It is concluded that melatonin has a lipid mobilizing action in the pigeon when administered
- during the scotophase.
- </p>
-
- <p>
- Arch Int Physiol Biochim 1983 Jul;91(2):115-20. <strong>Diurnal impact of locomotory activity and melatonin
- and N-acetylserotonin treatment on blood metabolite levels in the rainbow trout.</strong> John TM,
- Beamish FW, George JC. In rainbow trout forced to swim continuously at sustained speeds for six weeks,
- selected doses of melatonin or N-acetylserotonin (1.25 and 5.0 mg/kg body weight) injections caused no
- change in haematocrit. Melatonin did not produce any significant change in plasma glucose level either in
- the photophase or in the scotophase. However, diurnal variations were observed in the effect of melatonin on
- plasma free fatty acids (FFA). Melatonin was ineffective in causing<strong>
- any change in plasma FFA level during photophase but during scotophase, the higher dose (5.0 mg/kg)
- produced an increase in FFA while the lower dose (1.25 mg/kg) had no effect, N-acetylserotonin
- administration produced diurnal</strong> variation in its effect on both plasma glucose and FFA. The
- higher dose of N-acetylserotonin brought about a drop in plasma glucose level during photophase, but both
- doses were ineffective during scotophase. N-acetylserotonin produced no change in FFA during photophase, but
- during scotophase tended to lower FFA level. It is suggested that exercise shortens the time required to
- cause a hypoglycemic effect of N-acetylserotonin during photophase, blocks FFA release-inhibiting action of
- melatonin observed in photophase, and minimizes the time required for the FFA mobilizing action of melatonin
- in scotophase.
- </p>
- <p>
- J Neural Transm 1977;40(2):87-97. <strong>The adrenal medulla may mediate the increase in pineal melatonin
- synthesis induced by stress, but not that caused by exposure to darkness.</strong> Lynch HJ, Ho M,
- Wurtman RJ.
- </p>
- <p>
- Bull Acad Natl Med 2000;184(2):415-28; discussion 428-30. <strong>[Pulmonary toxicity of oxygen]</strong>
- [Article in French] Mantz JM, Stoeckel ME.
- </p>
-
- <p>
- Br J Pharmacol 1977 Dec;61(4):607-14. <strong>The action of melatonin on single amphibian pigment cells in
- tissue culture.</strong> Messenger EA, Warner AE.
- </p>
- <p>
- Oftalmol Zh 1989;(8):469-73. <strong>[The early diagnosis, evaluation of treatment results and modelling of
- certain aspects of the pathogenesis of retinal dystrophy]</strong>
- ; Mironova EM, Pavlova ON, Ronkina TI. The paper analyses results after a study of the functional state of
- pigmented epithelium and the retina in patients with a dry form of senile macular dystrophy as well as of
- experimental simulation of retinal dystrophy with the help of melatonin and its treatment by taurine.
- <strong>Melatonin in 10(-3) M concentration leads to development of dystrophic changes</strong> in pigmented
- epithelium and interacting with it structures, this being testified by remarkable lowering of EOG parameters
- and electron microscopic findings. Taurine in 10(-3) <strong>M concentration blocks the action of exogenic
- melatonin as well as has a pronounced positive action on metabolism of dystrophic changes in the
- pigmented epithelium and photoreceptors. Examination of patients with different stages of a dry form of
- senile</strong>
- macular dystrophy revealed statistically significant reduction of KA cEOG at the initial stage of the
- disease in the presence of normal ERG parameters. In 18% of patients, supernormal values of KA were
- recorded, that are likely to reflect the presence of "predystrophic hyperactivity" of the pigmented
- epithelium cells. In progression of the process, the further reduction of electrophysiologic values was
- recorded. The data obtained speaks about the important role of pigmented epithelium pathology in the
- pathogenesis of senile macular dystrophy and about high information value of the cEOG method for detection
- of early stages of the disease. It is believed that disturbances in melatonin metabolism can be one of
- causes leading to development of retinal dystrophy.
- </p>
- <p>
- J Clin Endocrinol Metab 1977 Oct;45(4):768-74. <strong>The effects of oral melatonin on skin color and on
- the release of pituitary hormones.</strong>
- Nordlund JJ, Lerner AB. "We studied the effects of prolonged ingestion of melatonin, 1 g per day, on skin
- color and the serum levels of pituitary hormones in 5 human subjects with hyperpigmented skin. Melatonin
- lightened hyperpigmented skin of one patient with untreated adrenogenital syndrome, but had no effect on
- three patients' skin with idiopathic hyperpigmentation and one patient with treated Addison's disease."
- </p>
- <p>
- Invest Ophthalmol 1976 Oct;15(10):869-72. <strong>Hormonal influences on photoreceptor damage: the pituitary
- gland and ovaries.</strong> Olafson RP, O'Steen WK. To determine whether the absence of pituitary or
- ovarian hormones would influence retinal degeneration, female albino rats were either hypophysectomized
- (HYPEX) or ovariectomized (OVEX) before pubery. Later, they were exposed to continuous light for periods up
- to 45 days. Retinas evaluated by light microscopic measurements showed damage to the outer nuclear layer
- (ONL) and photoreceptor layer in both the operated and intact, control rats. However, the degree of damage
- observed in retinas of HYPEX and OVEX rats was significantly less than that observed in retinas of intact
- rats exposed to the same lighting conditions. Therefore, hypophysectomy and ovariectomy, which influence the
- normal development of sexual maturation when performed on immature rats, significantly reduce photoreceptor
- damage in adult rats exposed to continuous light.
- </p>
- <p>
- Invest Ophthalmol Vis Sci 1996 Oct;37(11):2243-57. <strong>Retinal light damage in rats with altered levels
- of rod outer segment docosahexaenoate. Organisciak DT, Darrow RM, Jiang YL, Blanks JC.</strong>
-
- PURPOSE: To compare retinal light damage in rats with either normal or reduced levels of rod outer segment
- (ROS) docosahexaenoic acid. METHODS: Weanling male albino rats were maintained in a weak cyclic light
- environment and fed either a nonpurified control diet or a purified diet deficient in the linolenic acid
- precursor of docosahexaenoic acid (DHA). Half the rats on the deficient diet were given linseed oil,
- containing more than 50 mol% linolenic acid, once a week to maintain ROS DHA at near normal levels. Diets
- and linseed oil supplementation were continued for 7 to 12 weeks. To replenish DHA in their ROS, some
- 10-week-old rats on the deficient diet were given linseed oil three times a week for up to 3 additional
- weeks. Groups of animals were killed at various times for ROS fatty acid determinations or were exposed to
- intense green light using intermittent or hyperthermic light treatments. The extent of retinal light damage
- was determined biochemically by rhodopsin or photoreceptor cell DNA measurements 2 weeks after exposure and
- morphologically by light and electron microscopy at various times after light treatment. RESULTS: <strong
- >Rats maintained for 7 to 12 weeks on the linolenic acid-deficient diet had significantly lower levels of
- DHA</strong> and significantly higher levels of n-6 docosapentaenoic acid (22:5n-6) in their ROS than
- deficient-diet animals supplemented once a week with linseed oil or those fed the nonpurified control diet.
- As determined by rhodopsin levels and photoreceptor cell DNA measurements, deficient diet rats<strong>
- exhibited protection against retinal damage from either intermittent or hyperthermic light exposure.
- However, the unsaturated fatty acid content of ROS</strong> from all three dietary groups was the same
- and greater than 60 mol%. In 10 week-old deficient-diet rats given linseed oil three times a week, ROS DHA
- was unchanged for the first 10 days, whereas 22:5n-6 levels declined by 50%. After 3 weeks of treatment with
- linseed oil, ROS DHA and 22:5n-6 were nearly the same as in rats supplemented with linseed oil from weaning.
- The time course of susceptibility to retinal light damage, however, was different. Hyperthermic light damage
- in rats given linseed oil for only 2 days was the same as for rats always fed the deficient diet. Six days
- after the start of linseed oil treatment, retinal light damage was the same as in rats given the linseed oil
- supplement from weaning. Morphologic alterations in ROS of linseed oil-supplemented rats immediately after
- intermittent light exposure were more extensive than in either the deficient-diet animals or those fed the
- control diet. The deficient-diet rats also exhibited better preservation of photoreceptor cell nuclei and
- structure 2 weeks after exposure. CONCLUSIONS: Rats fed a diet deficient in the linolenic acid precursor of
- DHA are protected against experimental retinal light damage. The relationship between retinal light damage
- and ROS lipids does not depend on the total unsaturated fatty acid content of ROS; the damage appears to be
- related to the relative levels of DHA and 22:5n-6.
- </p>
- <p>
- Exp Neurol 1970 May;27(2):194-205.<strong>
- Retinal and optic nerve serotonin and retinal degeneration as influenced by photoperiod.</strong>
- O'Steen WK.
- </p>
- <p>
- Invest Ophthalmol Vis Sci 1982 Jan;22(1):1-7. <strong>Antagonistic effects of adrenalectomy and
- ether/surgical stress on light-induced photoreceptor damage.</strong> O'Steen WK, Donnelly JE.
- Light-induced damage to retinal photoreceptors in influenced by the endocrine status of the animal during
- the period of exposure. Experimental manipulation of the pituitary gland and of prolactin levels has been
- shown to affect retinal damage in rats exposed to visible light. When rats are experimentally stressed,
- prolactin secretion from the pituitary gland occurs as does secretion of adrenocorticotropic hormone (ACTH),
- which stimulates the release of adrenal cortical hormones. Since prolactin appears to influence retinal
- damage and since stressed animals have increased serum levels of prolactin, a comparison of photoreceptor
- damage in animals in which the adrenal glands were removed or which had been experimentally stressed was
- undertaken in this study. Adrenalectomized rats had thicker outer nuclear layer (ONL) measurements than
- those found in sham-operated animals. Stressed rats had severely damaged retinas with cystic degeneration
- and significantly reduced ONL thickness measurements as compared to retinas of unstressed and
- adrenalectomized rats. <strong>Therefore hormones of the pituitary-adrenal system appear to be involved in
- the damage to the retina by light, and this response may be related to an interaction or synergism
- between the adrenal gland, stress, and prolactin secretion.</strong>
- </p>
-
- <p>
- Brain Res 1990 Nov 26;534(1-2):99-105. <strong>Water deprivation protects photoreceptors against light
- damage.</strong> O'Steen WK, Bare DJ, Tytell M, Morris M, Gower DJ. "Photoreceptor cell death after
- light-damage and during aging in rats is associated with the hormonal status of the animal, as well as other
- environmental and intrinsic factors. Restricted caloric intake extends the life of rodents and is usually
- accompanied by a reduction in water consumption. In this study, male and female rats were placed on
- restricted water intake for either 3 or 7 days to induce dehydration." "Photoreceptor cells of 7-day,
- dehydrated male and female rats survived light-damage significantly better than those allowed water ad
- libitum; however, after 3 days of water restriction, only the male rats demonstrated protection from
- photodamage." "AVP increased by 350% during the 7-day period of dehydration. Protection of photoreceptors
- from light-damage in this study may be correlated with osmotically stimulated changes in the retinas of
- dehydrated animals."
- </p>
- <p>
- Brain Res 1985 Oct 7;344(2):231-9. <strong>Neuronal damage in the rat retina after chronic stress.</strong>
- O'Steen WK, Brodish A. Long-term exposure to escapable foot shock has been used to determine if chronic
- stress influences neuronal cell death in the retina of albino and pigmented rats. Histopathologic and
- morphometric approaches analyzed changes in photoreceptors and neurons of the bipolar and ganglion cell
- layers of the retina. Albino Fischer rats when exposed to chronic stress for 4-8 h daily for 1 week to 6
- months, developed severe retinal damage, as compared to unstressed control retinas, with reduction in
- photoreceptor and bipolar neurons, particularly in the superior central retina. The damage was observed in
- male and female rats, but males appeared to be more susceptible to the influence of stress than female
- animals. Ganglion cells were unaffected. Photoreceptor destruction did not occur in Long-Evans pigmented
- rats under identical experimental conditions. The results suggest that: <strong>input of the sensory
- stimulus, light, to the retina of stressed rats augmented neuronal damage and might be required for its
- initiation;</strong> and hormones and/or neurotransmitters associated with long-term chronic stress
- might be related to increased neuronal cell death in the mammalian retina.
- </p>
- <p>
- Invest Ophthalmol Vis Sci 1977 Oct;16(10):940-6. <strong>Effects of hypophysectomy, pituitary gland
- homogenates and transplants, and prolactin on photoreceptor destruction.</strong> O'Steen WK, Kraeer SL.
- "Prepubertal removal of the pituitary gland, which in young animals influences sexual maturation, reduces
- significantly the amount of retinal photoreceptor destruction when the rats are exposed to continuous
- illumination in adulthood. When crude pituitary gland homogenate is administered to adult rats
- hypophysectomized prior to puberty, photoreceptor destruction is more severe. Transplantation of whole
- pituitary glands to the kidney capsule of hypophysectomized rats also reduces the effect of pituitary gland
- removal and results in more extensive damage to receptor cells than found in hypophysectomized, adult
- animals. <strong>Hypophysectomized rats treated with prolactin had more severe retinal damage than
- untreated, hypophysectomized rats."</strong> "Results of these studies indicate the hormones of the
- pituitary gland have a regulatory influence on the severity of light-induced, retinal photoreceptor damage
- in the rat."
- </p>
- <p>
- Life Sci 1985 Nov 4;37(18):1743-6. <strong>Stress-induced synthesis of melatonin: possible involvement of
- the endogenous monoamine oxidase inhibitor (tribulin).</strong> Oxenkrug GF, McIntyre IM.
- </p>
- <p>
- Mech Ageing Dev 2000 Jan 10;112(3):169-83. <strong>Double bond content of phospholipids and lipid
- peroxidation negatively correlate with maximum longevity in the heart of mammals.</strong> Pamplona R,
- Portero-Otin M, Ruiz C, Gredilla R, Herrero A, Barja G.
- </p>
-
- <p>
- Prostaglandins Leukot Essent Fatty Acids 2001 Feb;64(2):75-80. <strong>Comparative studies on lipid
- peroxidation of microsomes and mitochondria obtained from different rat tissues: effect of retinyl
- palmitate.</strong> Piergiacomi VA, Palacios A, Catala A.
- </p>
- <p>
- Curr Eye Res 1992 Oct;11(10):939-53. <strong>Oxygen-induced retinopathy in the rat: hemorrhages and
- dysplasias may lead to retinal detachment.</strong> Penn JS, Tolman BL, Lowery LA, Koutz CA.
- </p>
- <p>
- Vision Res 1995 May;35(9):1247-64. <strong>Studies on the role of the retinal dopamine/melatonin system in
- experimental refractive errors in chickens.</strong>
-
- Schaeffel F, Bartmann M, Hagel G, Zrenner E.
- </p>
- <p>
- Exp Clin Endocrinol Diabetes 1997;105(2): 109-12. <strong>Melatonin</strong>
- <strong>
- and serotonin regulate the release of insulin-like growth factor-I, oxytocin and progesterone by
- cultured human granulosa cells.</strong> Schaeffer HJ, Sirotkin AV.
- </p>
- <p>
- Zh Evol Biokhim Fiziol 1989 Jan-Feb;25(1):52-9. <strong>[Seasonal characteristics of the functioning of the
- hypophysis-gonad system in the suslik</strong> Citellus parryi] Shvareva NV, Nevretdinova ZG. "In
- females, FSH was found in the blood in October, being absent from November to<strong>
- January; beginning from February, it may be found both in sleeping and active</strong> animals." <strong
- >"Estradiol secretion was noted in hibernating females, whereas progesterone was found in the blood only in
- May."</strong>
- </p>
-
- <p>
- J Pineal Res 1985;2(1):39-49. <strong>Melatonin and N-acetylserotonin stress responses: effects of type of
- stimulation and housing conditions.</strong> Seggie J, Campbell L, Brown GM, Grota LJ.
- </p>
- <p>
- Acta Ophthalmol Scand 2001 Aug;79(4):428-30. <strong>Presumed sertraline maculopathy.</strong> Sener EC,
- Kiratli H.
- </p>
- <p>
- Paediatr Perinat Epidemiol 1999 Apr;13(2):128-30. <strong>Effects of premature exposure to light: a
- credibility struggle.</strong> Silverman WA.
- </p>
-
- <p>
- J Pineal Res 1994 Oct;17(3):112-7. <strong>Direct influence of melatonin on steroid, nonapeptide hormones,
- and cyclic nucleotide secretion by granulosa cells isolated from porcine ovaries.</strong> Sirotkin AV.
- <strong>
- "It was found that melatonin is able to inhibit progesterone and stimulate estradiol secretion."</strong
- > "The present observations suggest a direct effect of melatonin on the steroid, nonapeptide hormone, and
- cyclic nucleotide release from porcine ovarian cells."
- </p>
- <p>
- J Pineal Res 1994 Oct;17(3):112-7. <strong>Direct influence of melatonin on steroid, nonapeptide hormones,
- and cyclic nucleotide secretion by granulosa cells isolated from porcine ovaries.</strong> Sirotkin AV.
- </p>
- <p>
- Prog Clin Biol Res 1989;312:229-49. <strong>Inhibitors of the arachidonic acid cascade in the management of
- ocular inflammation.</strong>
-
- Srinivasan BD, Kulkarni PS.
- </p>
- <p>
- J Nutr 2000 Dec;130(12):3028-33. <strong>Polyunsaturated (n-3) fatty acids susceptible to peroxidation are
- increased in plasma and tissue lipids of rats fed docosahexaenoic acid-containing oils.</strong> Song
- JH, Fujimoto K, Miyazawa T.<strong>
- "Thus, high incorporation of (n-3) fatty acids (mainly DHA) into plasma and tissue lipids due to
- DHA-containing oil ingestion may undesirably affect tissues by enhancing</strong>
- susceptibility of membranes to lipid peroxidation and by disrupting the antioxidant system."
- </p>
- <p>
- Acta Ophthalmol (Copenh) 1992 Feb;70(1):115-22. <strong>Effects of steady electric fields on human retinal
- pigment epithelial cell orientation and migration in culture.</strong> Sulik GL, Soong HK, Chang PC,
- Parkinson WC, Elner SG, Elner VM
- </p>
-
- <p>
- Ned Tijdschr Geneeskd 2001 Dec 29;145(52):2521-5. <strong>[Administration of glucocorticosteroids to
- premature infants: increasing evidence of adverse effects]</strong> [Article in Dutch] van Bel F.
- <strong>"Neonatal glucocorticosteroid therapy is increasingly being used for the prevention of chronic lung
- disease in very premature infants. In the short term this therapy is usually successful. There is,
- however, increasing evidence for long-term adverse effects. In particular there seems to be an increased
- chance of abnormal brain development, which later results in locomotory dysfunction, developmental delay
- and cerebral palsy.</strong>"
- </p>
- <p>
- Brain Res 1984 Feb 27;294(1):166-8. <strong>Pineal methoxyindoles depress calcium uptake by rat brain
- synaptosomes.</strong> Vacas MI, Keller Sarmiento MI, Cardinali DP.
- </p>
- <p>
- Ann N Y Acad Sci 1994 Nov 17;738:408-18. <strong>Serotonin binding proteins: an in vitro model system for
- monoamine-related neurotoxicity.</strong> Vauquelin G, Del Rio MJ, Pardo CV.
- </p>
-
- <p>
- J Hypertens Suppl 1985 Dec;3 Suppl 3:S107-9. <strong>Seasonal variation in the development of stress-induced
- systolic hypertension in the rat.</strong>
- Weinstock M, Blotnick S, Segal M. "Seasonal variation in blood pressure in human hypertensives prompted us
- to investigate whether such a phenomenon also occurs in rats made hypertensive by environmental stress."
- <strong>
- "Systolic pressure increased by 14-25 mmHg after 6-8 weeks of stress from October to January. Artificial
- environmental light for 15 h prevented development of hypertension by stress,
- </strong>
- which could also be reversed by acute administration of propranolol." "Hypertensive rats had significantly
- greater relative heart and adrenal weights. This phenomenon can be explained by amplification of<strong>
- sympathetic pressor activity by stress hormones, adrenaline, corticosterone and prolactin, under the
- influence of melatonin."</strong>
- </p>
- <p>
- Invest Ophthalmol Vis Sci 1992 May;33(6):1894-902. <strong>Melatonin increases photoreceptor susceptibility
- to light-induced damage.</strong> Wiechmann AF, O'Steen WK. <strong>"Pinealectomy has been shown to
- protect photoreceptors from light-induced damage, and melatonin treatment has been reported to increase
- the degree of photoreceptor damage in albino rats.</strong>" "The animals that received daily melatonin
- injections (100 micrograms) in the late afternoon (3 hr before lights off) for 1-3 days before photodamage
- showed an approximate 30% greater reduction compared with sham control animals in ONL thickness in the
- superior quadrant, the area most susceptible to light damage. Melatonin injections given after the
- photodamage did not affect ONL thickness. Although retinal susceptibility to light damage varied with time
- of day, the degree to which melatonin increased the degree of damage appeared unaffected by the time of day.
- These results suggest that melatonin may be involved in some aspects of photoreceptor sensitivity to light
- damage."
- </p>
-
- <p>
- J Neurochem 1986 Oct;47(4):1181-9. <strong>Effects of arachidonic acid on glutamate and gamma-aminobutyric
- acid uptake in primary cultures of rat cerebral cortical astrocytes and neurons.</strong> Yu AC, Chan
- PH, Fishman RA.
- </p>
-
- <p>
- © Ray Peat 2006. All Rights Reserved. www.RayPeat.com
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