Ledda
/
djledda-web

<html>
    <head><title>Altitude and Mortality</title></head>
    <body>
        <h1>
            Altitude and Mortality
        </h1>

        <p></p>
        <p>
            <em>Breathing pure oxygen lowers the oxygen content of tissues; breathing rarefied air, or air with carbon
                dioxide, oxygenates and energizes the tissues; if this seems upside down, it's because medical
                physiology has been taught upside down. And respiratory physiology holds the key to the special
                functions of all the organs, and to many of their basic pathological changes.</em>
        </p>
        <p>
            <strong><em>Stress, shock, inflammation, aging, and organ failure are, in important ways, respiratory
                    problems.</em></strong>
        </p>

        Definitions <strong>
            Haldane effect:
        </strong>Oxygen displaces carbon dioxide from hemoglobin, in proportion to its partial (specific) pressure.
        <strong>
            Bohr effect:</strong> Carbon dioxide (or acidity) displaces oxygen from hemoglobin. <strong>
            Lactic acidemia:
        </strong>The presence of lactic acid in the blood. <strong>
            Alkalosis:</strong> A pH of the blood above 7.4. <strong>
            Acidosis:
        </strong>A blood pH below 7.4. <strong>
            Lactate paradox:</strong> The reduced production of lactic acid at a given work rate at high altitude.
        Muscle work efficiency may be 50% greater at high altitude. ATP wastage is decreased.<p></p>
        <p>
            There are some popular medical ideas that obstruct clear thinking about respiration. One is that high
            altitude deprives you of oxygen, and is likely to be bad for people with heart disease and cancer. Another
            is that breathing pure oxygen helps sick people to oxygenate their tissues while exerting less effort in
            breathing. These are both exactly wrong, and the errors have been explored in quite a few publications, but
            the ideas persist in the culture to such a degree that our <strong><em>perceptions and intuitions
                </em></strong>have been misled, making closely related things seem to be unrelated. In this culture, it
            is hard to see that heart disease, cancer, and cataracts all involve a crucial respiratory defect, with the
            production of too much lactic acid and too little carbon dioxide, which leads to a "swelling
            pathology"<strong>:</strong> A pathological retention of water. The swollen heart beats poorly, the swollen
            lens turns milky, other cells divide rapidly as a result of swelling.
        </p>
        <p>
            People who live at very high altitudes live significantly longer<strong>;</strong> they have a lower
            incidence of cancer (Weinberg, et al., 1987) and heart disease (Mortimer, et al., 1977), and other
            degenerative conditions, than people who live near sea level. As I have written earlier, I think the lower
            energy transfer from cosmic radiation is likely to be a factor in their longevity, but several kinds of
            evidence indicate that it is the lower oxygen pressure itself that makes the biggest contribution to their
            longevity.
        </p>

        <p>
            "Mountain sickness" is a potentially deadly condition that develops in some people when they ascend too
            rapidly to a high altitude. Edema of the lungs and brain can develop rapidly, leading to convulsions and
            death. The standard drug for preventing it is acetazolamide, which inhibits carbonic anhydrase and causes
            carbon dioxide to be retained, creating a slight tendency toward acidosis. This treatment probably mimics
            the retention of carbon dioxide that occurs naturally in altitude adapted people. The reasons for mountain
            sickness, and the reasons for the low incidence of heart disease, cancer, cataracts, etc., at high altitude,
            offer clues to the prevention of death and deterioration from many other causes.
        </p>
        <p>
            When the weather in a particular place is cool, sunny and dry (which in itself is very good for the health)
            the atmospheric pressure usually is higher than average. Although sunny dry weather is healthful,<strong>
                periods of higher pressure correspond to an increased incidence of death</strong>
            from heart disease and strokes.
        </p>
        <p>
            The Haldane-Bohr effect describes the fact that oxygen and carbon dioxide destabilize each other"s binding
            to hemoglobin. When oxygen pressure is high, the blood releases its carbon dioxide more easily. In stormy
            weather, or at high altitude, the lower oxygen pressure allows the body to retain more carbon dioxide.
            Carbon dioxide, produced in the cells, releases oxygen into the tissues, relaxes blood vessels, prevents
            edema, eliminates ammonia, and increases the efficiency of oxidative metabolism.
        </p>
        <p>
            Hyperventilation, breathing excessively and causing too much carbon dioxide to be lost, is similar to being
            in the presence of too much oxygen<strong>;</strong> it"s similar to being at low altitude with high
            atmospheric pressure, only worse. Therefore, the physiological events produced by hyperventilation can give
            us an insight into what happens when the atmospheric pressure is low, by looking at the events in reverse.
            Likewise, breathing 100% oxygen has known harmful consequences, which are very similar to those produced by
            hyperventilation.
        </p>

        <p>
            Hyperventilation is defined as breathing enough to produce respiratory alkalosis from the loss of carbon
            dioxide. Lactic acid is produced in response to the alkalosis of hyperventilation.
        </p>
        <p>
            Breathing too much oxygen displaces too much carbon dioxide, provoking an increase in lactic acid<strong
            >;</strong> too much lactate displaces both oxygen and carbon dioxide. Lactate itself tends to suppress
            respiration.
        </p>
        <p>
            Oxygen toxicity and hyperventilation create a systemic deficiency of carbon dioxide. It is this carbon
            dioxide deficiency that makes breathing more difficult in pure oxygen, that impairs the heart"s ability to
            work, and that increases the resistance of blood vessels, impairing circulation and oxygen delivery to
            tissues. In conditions that permit greater carbon dioxide retention, circulation is improved and the heart
            works more effectively. Carbon dioxide inhibits the production of lactic acid, and lactic acid lowers carbon
            dioxide's concentratrion in a variety of ways..
        </p>
        <p>
            When carbon dioxide production is low, because of hypothyroidism, there will usually be some lactate
            entering the blood even at rest, because adrenalin and noradrenalin are produced in large amounts to
            compensate for hypothyroidism, and the adrenergic stimulation, besides mobilizing glucose from the glycogen
            stores, stimulates the production of lactate. The excess production of lactate displaces carbon dioxide from
            the blood, partly as a compensation for acidity. The increased impulse to breath ("ventilatory drive")
            produced by adrenalin makes the problem worse, and lactate can promote the adrenergic response, in a vicious
            circle..
        </p>
        <p>
            Since the 1920s when A. V. Hill proposed that the prolonged increase in oxygen consumption after a short
            period of intense work, the "oxygen debt," was equivalent to the amount of lactic acid that had entered the
            circulation from the muscles" anaerobic work, and that it had to be disposed of by oxidative processes,
            physiology textbooks have given the impression that lactic acid accumulation was exactly the same as the
            oxygen debt. In reality, several things are involved, especially the elevation of temperature produced by
            the intense work. Increased temperature raises oxygen consumption independently of lactic acid, and lower
            temperature decreases oxygen consump-tion, even when lactic acid is present.
        </p>

        <p>
            The idea of the "oxygen debt" produced by exercise or stress as being equivalent to the accumulation of
            lactic acid is far from accurate, but it"s true that activity increases the need for oxygen, and also
            increases the tendency to accumulate lactic acid, which can then be disposed of over an extended time, with
            the consumption of oxygen. This relationship between work and lactic acidemia and oxygen deficit led to the
            term "lactate paradox" to describe the lower production of lactic acid during maximal work at high altitude
            when people are adapted to the altiude. Carbon dioxide, retained through the Haldane effect, accounts for
            the lactate paradox, by inhibiting cellular excitation and sustaining oxidative metabolism to consume
            lactate efficiently.
        </p>
        <p>
            The loss of carbon dioxide from the lungs in the presence of high oxygen pressure, the shift toward
            alkalosis, by the Bohr-Haldane effect increases the blood"s affinity for oxygen, and restricts its delivery
            to the tissues, but because of the abundance of oxygen in the lungs, the blood is almost competely saturated
            with oxygen.
        </p>
        <p>
            At high altitude, the slight tendency toward carbon dioxide-retention acidosis decreases the blood"s
            affinity for oxygen, making it more available to the tissues. It happens that lactic acid also affects the
            blood"s oxygen affinity, though not as strongly as carbon dioxide. <strong>
                However, lactic acid doesn"t vaporize as the blood passes through the lungs, so its effect on the lungs"
                ability to oxygenate the blood is the opposite of the easily exchangeable carbon dioxide"s.
            </strong>
            Besides<strong> </strong>dissociating oxygen from hemoglobin, lactate also displaces carbon dioxide from its
            (carbamino) binding sites on hemoglobin. If it does this in hemoglobin, it probably does it in many other
            places in the body.
        </p>
        <p>
            According to Meerson, ascending more than 200 feet per day produces measurable stress. People seldom notice
            the effects of ascending a few thousand feet in a day, but it has been found that a large proportion of
            people have bleeding into the retina when they ascend to 10,000 feet without adequate adaptation.
            Presumably, similar symptomless bleeding occurs in other organs, but the retina can be easily inspected.
        </p>

        <p>
            If hypothyroid people, with increased adrenalin and lactate, are hyperventilating even at rest and at sea
            level, when they go to a high altitude where less oxygen is available, and their absorption of oxygen is
            impaired by lactic acidemia, <strong>their "oxygen debt," conceived as circulating lactic acid, is easily
                increased, intensifying their already excessive "ventilatory drive," and in proportion to the lactic
                acid oxygen debt, oxygen absorption is further inhibited.</strong>
        </p>
        <p>
            The lactic acid has to be disposed of, but their ability to extract oxygen is reduced. The poor oxygenation,
            and the increased lactic acid and free fatty acids cause blood vessels to become leaky, producing edema in
            the lungs and brain. <strong>This is very similar to the "multiple organ failure" that occurs in
                inflammatory conditions, bacteremia, congestive heart failure, cancer, and trauma.</strong>
        </p>
        <p>
            <strong>Otto Warburg established that lactic acid production even in the presence of oxygen is a fundamental
                property of cancer.</strong> It is, to a great degree, the lactic acid which triggers the defensive
            reactions of the organism, leading to tissue wasting from excessive glucocorticoid hormone. The cancer"s
            production of lactic acid creates the same kind of internal imbalance produced by hyperventilation, and if
            we look at the physiology of hyperventilation in the light of Warburg"s description of cancer,
            hyperventilation imitates cancer metabolism, by producing lactic acid "even in the presence of oxygen."
            Lactate, a supposedly benign metabolite of the cancer cells, which appears in all the other degenerative
            conditions, including obesity, diabetes, Alzheimer"s disease, multiple sclerosis, is itself a central factor
            in the degenerative process.
        </p>
        <p>
            Working out the mechanisms involved in susceptibility to altitude sickness will clarify the issues involved
            in the things that cause most people to die. At first, all of these changes occur in the regulatory systems,
            and so can be corrected.
        </p>

        <p>
            The vitality of the mitochondria, their capacity for oxidative energy production, is influenced by nutrition
            and hormones. In healthy people, mitochondria work efficiently at almost any altitude, but people with
            damaged or poorly regulated mitochondria are extremely susceptible to stress and hyperventilation.
            Progesterone, testosterone, and thyroid (T3 and T2) are protective of normal mitochondrial function, by both
            local and systemic effects.
        </p>
        <p>
            The changes that occur in malnutrition and hypothyroidism affect the mitochondria in a multitude of ways,
            besides the local effects of the thyroid and progesterone deficiency.
        </p>
        <p>
            Increased estrogen, nitric oxide, excitatory amino acids, cortisol, lactate, free unsaturated fatty acids,
            prolactin, growth hormone, histamine, serotonin, tumor necrosis factor and other pro-inflammatory cytokines
            and kinins, and a variety of prostaglandins and eicosanoids, have been identified as anti-mitochondrial,
            anti-respiratory agents. Edema itself can be counted among these agents.<strong> </strong>
            (Carbon dioxide itself directly reduces tissue edema, as can be seen in studies of the cornea.)<strong>
                Thyroid, progesterone, magnesium, glucose, and saturated fatty acids are among the central protective
                elements.</strong>
        </p>

        <p>
            The similarity of the changes occurring under the influence of estrogen excess, oxygen deprivation, aging,
            and ionizing radiation are remarkable. People who think that radiation"s biological effects are mainly on
            the DNA, and that estrogen acts through "estrogen receptors," aren"t interested in the parallels, but the
            idea of a common respiratory defect, activating common pathways, suggests that there is something useful in
            the perception that irradiation, hypoxia, and aging have estrogenic effects.
        </p>
        <p>
            Irradiation by ultraviolet, gamma, or x-rays, and even by blue light, is damaging to mitochondrial
            respiration. All of the ionizing radiations produce immediate and lingering edema, which continues to damage
            metabolism in a more or less permanent way, apart from any detectable mutagenic actions. The amount of water
            taken up following irradiation can be 20% to 30% of the normal weight, which is similar to the amount of
            swelling that intense work produces in a muscle, and to the weight increase under hormonal imbalances. The
            energy changes produced by irradiation in, for example, the heart, appear to accelerate the changes produced
            by aging. Since unsaturated fats accumulate in the respiratory system with aging, and are targets for
            radiation damage, the involvement of these fats in all sorts of antirespiratory degenerative processes
            deserves more attention. Darkness, like irradiation, excess lactate, and unsaturated fats, has the
            diabetes-like effect of greatly reducing the ability of muscle to absorb sugar, while light stimulates
            respiration..
        </p>
        <p>
            When the ideas of "stress," "respiratory defect," and "hyperventilation" are considered together, they seem
            practically interchangeable.
        </p>
        <p>
            The presence of lactic acid, which indicates stress or defective respiration, interferes with energy
            metabolism in ways that tend to be self-promoting. Harry Rubin"s experiments demonstrated that cells become
            cancerous before genetic changes appear. <strong>The mere presence of lactic acid can make cells more
                susceptible to the transformation into cancer cells.
            </strong>(Mothersill, et al., 1983.) The implications of this for the increased susceptibility to cancer
            during stress, and for the increased resistance to cancer at high altitude, are obvious.
        </p>
        <p>
            Blocking the production of lactic acid can make cells more resistant (Seymour and Mothersill, 1988)<strong
            >;</strong>

            if lactic acid were merely a useful fuel, it"s hard to see how poisoning its formation could improve cell
            survival. But it happens to be an energy-disruptive fuel, interfering with carbon dioxide metabolism, among
            other things.
        </p>
        <p>
            Hyperventilation is present in hypothyroidism, and is driven by adrenalin, lactate, and free fatty acids.
            Free fatty acids and lactate impair glucose use, and promote edema, especially in the lungs. Edema in the
            lungs limits oxygen absorption. Swelling of the brain, resulting from increased vascular permeability and
            the entry of free fatty acids, reduces its circulation and oxygenation<strong>;</strong> lactic acidemia
            causes swelling of glial cells. Swelling of the endothelium increases vascular resistance by making the
            channel narrower, eventually affecting all organs. Cells of the immune system release tumor necrosis factor
            and other inflammatory cytokines, and the bowel becomes more permeable, allowing endotoxin and even bacteria
            to enter the blood. Endotoxin impairs mitochondria, increases estrogen levels, causes Kupffer cells in the
            liver to produce more tumor necrosis factor, etc.. Despite its name, tumor necrosis factor stimulates the
            growth and metastasis of some types of cancer. Dilution of the body fluids, which occurs in hypothyroidsim,
            hyperestrogenism, etc., stimulates tumor growth.
        </p>
        <p>
            The inflammatory factors that can promote cell growth can, with just slight variation, deplete cellular
            energy to the extent that the cells die from the energetic cost of the repair process, or mutate from
            defective repairs. Niacinamide can have an "antiinflammatory" function, preventing death from multiple organ
            failure, by interupting the reactions to nitric oxide and peroxynitrile (Cuzzocrea, et al., 1999). The
            cells" type, environment, and history determine the different outcomes.
        </p>
        <p>
            Cataracts, cancer, congestive heart failure, seemingly such different degenerative problems, have the same
            sort of metabolic problem, leading to the abnormal absorption of water by cells, disrupting their normal
            functions.
        </p>
        <p>
            The same simple metabolic therapies, such as thyroid, progesterone, magnesium, and carbon dioxide, are
            appropriate for a great range of seemingly different diseases. Other biochemicals, such as adenosine and
            niacinamide, have more specific protective effects, farther downstream in the "cascade" effects of stress.
        </p>

        <p>
            There are many little cliches in the medical culture that prevent serious thought about integral
            therapy<strong>:</strong> "Progesterone is the pregnancy hormone," "thyroid makes your heart work too hard,"
            "thyroid uncouples mitochondrial phosphorylation," "magnesium has nothing to do with thyroid or
            progesterone," "lactate provides energy," etc. But many of these minor cliches are held in place by deep
            theoretical errors about the nature of cells and organisms. Once those have been corrected, there should be
            progress toward more powerful integral therapies.
        </p>
        <p><h3>REFERENCES</h3></p>
        <p>
            Cell Biol Int Rep 1983 Nov;7(11):971-80.<strong>
                Lactate-mediated changes in growth morphology and transformation frequency of irradiated C3H 10T1/2
                cells.</strong> Mothersill C, Seymour CB, Moriarty M. Treatment of mammalian cells with lactate or
            inhibitors of glycolysis alters their radiation response, particularly in the low dose region of the dose
            response curve. The occurrence of <strong>both high lactate levels and high glycolytic metabolism in
                tumours</strong> is well known and therefore the effect of lactate on a cell line sensitive to radiation
            induced transformation was examined using a single exposure to Cobalt 60 gamma rays as the carcinogen
            challenge. The results indicate that cells treated with <strong>
                5mM lactate before irradiation exhibit changes in morphology and growth rate and that the transformation
                frequency is increased by three to ten fold following 24 hours lactate treatment just prior to
                irradiation.
            </strong>
            Examination of radiation survival curves showed a positive correlation between transformation frequency and
            size of the shoulder, but increasing transformation frequency was associated with a decrease in Do. A
            mechanism involving altered Redox potential in lactate treated cells is suggested. The results are discussed
            in terms of their possible significance for radiotherapy.
        </p>
        <p>
            <strong>Radiat Environ Biophys 1988;27(1):49-57. The effect of glycolysis</strong>
            <strong>
                inhibitors on the radiation response of CHO-K1 cells. Seymour CB, Mothersill C Saint Luke's Hospital,
                Rathgar, Dublin, Ireland. Exposure of CHO-K1 cells to three different inhibitors of glycolysis, prior to
                treatment with a single dose of ionising radiation, reduced their survival. The effects were
                concentration-dependent but occurred under all conditions where cells were exposed to the inhibitors
                prior to irradiation. The results are similar to those obtained by this group when glycolysis was
                altered using analogues of D-glucose or by blocking the pyruvate----lactate reaction using added lactate
                or oxamate. They support data from other workers suggesting a role for energy metabolism in the final
                expression of radiation damage.
            </strong>
        </p>
        <p>
            Crit Care Med 1999 Aug;27(8):1517-23. <strong>Protective effect of poly(ADP-ribose) synthetase inhibition on
                multiple organ failure after zymosan-induced peritonitis in the rat.</strong> Cuzzocrea S, Zingarelli B,
            Costantino G, Sottile A, Teti D, Caputi AP
        </p>
        <p>
            Eur J Cancer 1975 May;11(5):365-371. <strong>Cancer and altitude. Does intracellular pH regulate cell
                division?</strong> Burton AC.<strong> </strong>
        </p>

        <p>
            <strong>Monaldi Arch Chest Dis 1999 Aug;54(4):365-72. The pathophysiology of hyperventilation syndrome.
                Folgering H.</strong> Dept Pulmonology Dekkerswald, University of Nijmegen, Groesbeek, The Netherlands..
            <strong>Hyperventilation is defined as breathing in excess of the metabolic needs of the body, eliminating
                more carbon dioxide than is produced, and, consequently, resulting in respiratory alkalosis and an
                elevated blood pH.</strong> The traditional definition of hyperventilation syndrome describes "a
            syndrome, characterized by a variety of somatic symptoms induced by physiologically inappropriate
            hyperventilation and usually reproduced by voluntary hyperventilation". The spectrum of symptoms ascribed to
            hyperventilation syndrome is extremely broad, aspecific and varying. They stem from virtually every tract,
            and can be caused by physiological mechanisms such as low Pa,CO2, or the<strong>
                increased sympathetic adrenergic tone.</strong> Psychological mechanisms also contribute to the
            symptomatology, or even generate some of the symptoms. Taking the traditional definition of hyperventilation
            syndrome as a starting point, there should be three elements to the diagnostic criterion: 1) the patient
            should hyperventilate and have low Pa,CO2, 2) somatic diseases causing hyperventilation should have been
            excluded, and 3) the patient should have a number of complaints which are, or have been, related to the
            hypocapnia. Recent studies have questioned the tight relationship between hypocapnia and complaints.
            However, the latter can be maintained and/or elicited when situations in the absence of hypocapnia in which
            the first hyperventilation and hypocapnia was present recur. Thus, the main approach to diagnosis is the
            detection of signs of (possible) dysregulation of breathing leading to hypocapnia. The therapeutic approach
            to hyperventilation syndrome has several stages and/or degrees of intervention: psychological counselling,
            physiotherapy and relaxation, and finally drug therapy. Depending on the severity of the problem, one or
            more therapeutic strategies can be chosen.
        </p>
        <p>
            N Engl J Med 1977 Mar 17;296(11):581-585.<strong>
                Reduction in mortality from coronary heart disease in men residing at high altitude.</strong> Mortimer
            EA Jr, Monson RR, MacMahon B In New Mexico, where inhabited areas vary from 914 to over 2135 m above sea
            level, we compared age-adjusted mortality rates for arteriosclerotic heart disease for white men and women
            for the years 1957-1970 in five sets of counties, grouped by altitude in 305-m (1000-foot) increments. The
            results show a serial decline in mortality from the lowest to the highest altitude for males but not for
            females. Mortality rates for males residing in the county groups higher than 1220 m in order of ascending
            altitude <strong>were 98, 90, 86 and 72 per cent of that for the county group below 1220-m altitude (P less
                than 0.0001).</strong> The results do not appear to be explained by artifacts in ascertainment,
            variations in ethnicity or urbanization. A possible explanation of the trend is that adjustment to residence
            at high altitude is incomplete and daily activities therefore represent greater exercise than when
            undertaken at lower altitudes.
        </p>

        <p>
            Br Med J 1980 Jan 5;280(6206):5. Cardiovascular mortality and altitude.
        </p>
        <p>
            Radiat Res 1987 Nov;112(2):381-390. <strong>Altitude, radiation, and mortality from cancer and heart
                disease.</strong> Weinberg CR, Brown KG, Hoel DG. The variation in background radiation levels is an
            important source of information for estimating human risks associated with low-level exposure to ionizing
            radiation. Several studies conducted in the United States, correlating mortality rates for cancer with
            estimated background radiation levels, found an unexpected inverse relationship. Such results have been
            interpreted as suggesting that low levels of ionizing radiation may actually confer some benefit. An
            environmental factor strongly correlated with background radiation is altitude. Since there are important
            physiological adaptations associated with breathing thinner air, such changes may themselves influence risk.
            We therefore fit models that simultaneously incorporated altitude and background radiation as predictors of
            mortality. The <strong>negative correlations with background radiation</strong> seen for <strong>mortality
                from arteriosclerotic heart disease and cancers of the lung, the intestine, and the breast</strong>
            disappeared or became positive once altitude was included in the models. <strong>By contrast, the
                significant negative correlations with altitude persisted with adjustment for radiation. Interpretation
                of these results is problematic, but recent evidence implicating reactive forms of oxygen in
                carcinogenesis and atherosclerosis may be relevant. We conclude that the cancer correlational studies
                carried out in the United States using vital statistics data do not in themselves demonstrate a lack of
                carcinogenic effect of low radiation levels, and that reduced oxygen pressure of inspired air may be
                protective against certain causes of death.
            </strong>
        </p>
        <p>
            Biull Eksp Biol Med 1993 Jun;115(6):576-578. <strong>[The effect of high-altitude ecological and
                experimental stresses on the thrombocyte-vascular wall system].</strong> [Article in Russian].
            Bekbolotova AK, Lemeshenko VA, Aliev MA. Experiments in animals (rats) and examinations of the population of
            high-altitude shepherds were used to study the functional system "Thrombocytes-Vessel Wall" (STVW) for
            evaluation of the organism ecological adaptation to "pure" high-altitude stress, with and without
            combination with experimental-adrenergic cardionecrosogenic stress (ACNS, in rats). The adaptive increase of
            antiaggregation prostacyclin activity of the aorta in rats and PGI2 reaction of vessels in human population
            of high-altitude in mountains (2000, 3000-3500 m) were found to be a common biologist regularity. The<strong
            >
                adaptive increase of coronary reserve of the heart and vasodilatator-antiaggregation status in
                high-altitude shepherds correlated with an increase of antiaggregation activity of the aorta and
                decrease of spontaneous aggregation of the thrombocytes in rats under conditions of more prolonged
                adaptation to high-altitude ecological stress.
            </strong>
        </p>

        <p>
            Diabetologia 1982 Jun;22(6):493. <strong>Measurement of glycosylated haemoglobin at high altitudes.</strong>
            Paisey R, Valles V, Arredondo G, Wong B, Lozano-Castaneda O.
        </p>
        <p>
            <strong>[Change in the ultrastructure of rat myocardium under the influence of 12-months' adaptation to high
                altitude]</strong> Zhaparov B; Mirrakhimov MM. Biull Eksp Biol Med, 1977 Jul, 84:7, 109-12. The right
            and left ventricle myocardium of rats was studied in the course of a 12-month period of adaptation to high
            altitude (3200 m above the sea level). A long-term exposure of the animals to the high altitude led the
            development of ventricular hypertrophy mostly of the right, and partly of the left ventricle.<strong>
                Hyperplasia and hypertrophy of individual organellae, particularly mitochondria</strong>, were found in
            most cardiomyocytes of both ventricles. In animals adapted to the high altitude the mitochondrial succinic
            dehydrogenase activity was more pronounced than in control ones. The results obtained testified to the
            enhanced intracellular metabolism reflecting myocardial compensatory adaptive responses.
        </p>
        <p>
            <strong>[Morphologic characteristics of the hearts of argali continuously dwelling at high mountain
                altitudes]</strong>, Zhaparov B; Kamitov SKh; Mirrakhimov MM, Biull Eksp Biol Med, 1980 Apr, 89<strong
            >:</strong>4, 498-501 The hearts of argali [wild sheep] living at 3800-5000 m above the sea level were
            examined.<strong>
                Macroscopy showed complete absence of fatty tissue under the epicardium.</strong> Increased number of
            the capillaries surrounding cardiomyocytes, intercalated discs in many zones of the myocardium, sharp
            thickening giving pronounced cross lines of myofibrils were revealed on semithin and ultrathin sections. The
            data obtained demonstrate specificity of the heart structure of argali and are<strong>
                discussed from the standpoint of increased compensatory-adaptive changes in the test organ, these
                changes being associated with its enhanced function provoked by high altitude conditions.
            </strong>
        </p>

        <p>
            J Dev Physiol 1990 Sep;14(3):139-46. <strong>Effect of lactate and beta-hydroxybutyrate infusions on brain
                metabolism in the fetal sheep.</strong>
            <hr />
            <strong>Despite large increases in fetal arterial lactate and beta-hydroxybutyrate during the respective
                infusions, no significant uptake of either substrate was demonstrated. However during both types of
                infusion, the brain arterio-venous difference for glucose decreased 30% (P less than 0.05). Since the
                brain arterio-venous difference for oxygen was unchanged, and blood flow to the cerebral hemispheres
                (measured in 11 studies) was also unchanged, the infusions appeared to cause a true decrease in brain
                glucose uptake. This decrease paralleled the rise in lactate concentration during lactate infusions, and
                the rise in lactate and butyrate</strong> concentrations during the butyrate infusions. Both substrates
            have metabolic actions that may inhibit brain glucose uptake. <strong>We speculate that the deleterious
                effects of high lactate and ketone states in the perinatal period may in part be due to inhibition of
                brain glucose uptake.</strong>
        </p>
        <p>
            Hypertens 1995 Feb;9(2):119-22. <strong>
                Pressor effect of hyperventilation in healthy subjects.</strong> Todd GP, Chadwick IG, Yeo WW, Jackson
            PR, Ramsay LE University Department of Medicine and Pharmacology, Royal Hallamshire Hospital, Sheffield, UK
            Hyperventilation is an important feature of panic disorder, and an association has been reported between
            panic disorder and hypertension. We have examined the effect of hyperventilation on the blood pressure (BP)
            of healthy subjects. Twenty six subjects were randomised in a balanced two-period cross-over study to
            compare the effects of hyperventilation with that of normal breathing on sitting BP, heart rate and the
            electrocardiogram. Each study phase lasted 40 min, with 15 min of baseline observation, 5 min of
            hyperventilation or normal breathing, and 20 min of continued<strong>
                observation. Hyperventilation significantly increased SBP by 8.9 mm Hg (95% CI 3.8-13.8, P &lt; 0.01),
                diastolic blood pressure by 8.2 mm Hg (95% CI 1.7-14.7, P &lt; 0.05), mean arterial pressure by 10.0 mm
                Hg (95% CI 3.3-16.7, P &lt; 0.01) and heart rate by 36 beats/min (95% CI 31-44, P &lt; 0.01). The
                changes in diastolic and mean arterial pressure correlated significantly with the total</strong>
            <hr />
            <strong>
                Intravenous infusion of free fatty acid (FFA) 20 mg.kg-1.min-1 produces pulmonary edema, hypoxemia,
                hyperventilation and increase in the alveolar surfactant content in rabbits in less than 15</strong>
            min.
        </p>

        <p>
            Respiration 1986;49(3):187-94. <strong>Role of hypocapnia in the alveolar surfactant increase induced by
                free fatty acid intravenous infusion in the rabbit.</strong>
            Oyarzun MJ, Donoso P, Quijada D<strong>. Intravenous infusion of free fatty acid (FFA) produces an increase
                in the alveolar surfactant pool of the rabbit and pulmonary edema, hyperventilation, hypoxemia and
                hypocapnia. Previous studies suggested that alveolar PCO2 would be a regulator of intracellular storages
                of surfactant. In order to</strong>
            <hr />
        </p>
        <p>
            Farmakol Toksikol 1977. Sep-Oct; 40(5):620-3..<strong>
                [Effect of combinations of apressin, obsidan, diprazin, adenosine, NAD and nicotinamide on the
                resistance of rats to hypoxia and on carbohydrate metabolic indices].</strong> [Article in Russian]
            Abakumov GZ As evidenced from experiments on rats, a combined application of apressin with obsidan and
            diprazine, and also of adenozine with nicotine-amidadenine-dinucleotide (NAD), as well as of adeozine with
            nicotine amide potentiates the protective effect of these substances in hypobaric hypoxia, increases the
            resistance of the animals to cerebral ischemia, <strong>brings down the excess lactate level and raises the
                redoz potential of the system lactic-acid-pyruvic</strong> acid in the brain of rats exposed to the
            effects of rarefied atmosphere.
        </p>

        <p>
            Schweiz Med Wochenschr 1977 Nov 5;107(44):1585-6. <strong>[Protective effect of pyridoxilate on the hypoxic
                myocardium. Experimental studies].</strong> [Article in French] Moret PR, Lutzen U The protective action
            of piridoxilate on hypoxic myocardium has been studied on rats in acute hypoxia (isolated heart, perfused
            with a non-oxygenated solution) and in prolonged hypoxia (3 days at high [3454 m] altitude). Piridoxilate
            maintained a higher ATP level with a much lower production of lactate. <strong>The mechanisms of action of
                piridoxilate are probably fairly similar to those of Na dichloracetate</strong>.
        </p>
        <p>
            J. Appl Physiol 1991 Apr;70(4):1720-30. .<strong>Metabolic and work efficiencies during exercise in Andean
                natives.</strong> Hochachka PW, Stanley C, Matheson GO, McKenzie DC, Allen PS, Parkhouse WS Department
            of Zoology, University of British Columbia, Vancouver, Canada. <strong>
                Maximum O2 and CO2 fluxes during exercise were less perturbed by hypoxia in Quechua natives</strong>
            from the Andes than in lowlanders. In exploring how this was achieved, we found that, <strong>for a given
                work rate, Quechua highlanders at 4,200 m accumulated substantially less lactate
            </strong>than lowlanders at sea level normoxia (approximately 5-7 vs. 10-14 mM) despite hypobaric hypoxia.
            This phenomenon, known as the lactate paradox, was entirely refractory to normoxia-hypoxia transitions. In
            lowlanders, the lactate paradox is an acclimation; however, in Quechuas, the lactate paradox is an
            expression of metabolic organization that did not deacclimate, at least over the 6-wk period of our study.
            Thus it was concluded that this metabolic organization is a developmentally or genetically fixed
            characteristic selected because of the <strong>efficiency advantage of aerobic metabolism (high ATP yield
                per mol of substrate metabolized) compared with anaerobic glycolysis.</strong> Measurements of
            respiratory quotient indicated preferential use of carbohydrate as fuel for muscle work, which is also
            advantageous in hypoxia because it maximizes the yield of ATP per mol of O2 consumed. Finally, minimizing
            the cost of muscle work was also reflected in energetic efficiency as classically defined (power output per
            metabolic power input);<strong>
                this was evident at all work rates but was most pronounced at submaximal work rates (efficiency
                approximately 1.5 times higher than in lowlander athletes).</strong> Because plots of power output vs.
            metabolic power input did not extrapolate to the origin, it was concluded 1) that exercise in both groups
            sustained a significant ATP expenditure not convertible to mechanical work but 2) that this expenditure was
            downregulated in Andean natives by thus far unexplained mechanisms.
        </p>

        <p>
            Br J Anaesth 1975 Jun;47(6):669-78. <strong>Effect of CO2 on myocardial contractility and aortic input
                impedance during anaesthesia.</strong> Foex P, Prys-Roberts C. The haemodynamic responses to hypocapnia
            and hypercapnia have been studied in the dog during intermittent positive pressure ventilation under
            halothane anaesthesia (1% halothane in oxygen) and under nitrous oxide anaesthesia (30% oxygen in nitrous
            oxide). In the absence of significant<strong>
                variations of either myocardial contractility or left ventricular end-diastolic pressure, the changes of
                stroke volume and cardiac output (diminution because of hypocapnia, augmentation because of hypercapnia)
                were determined by alterations of systemic vascular resistance (augmentation because of hypocapnia,
                diminution because of hypercapnia).
            </strong>
        </p>
        <p>
            J Appl Physiol 1991 May;70(5):1963-76.<strong>
                Skeletal muscle metabolism and work capacity: a 31P-NMR study of Andean natives and lowlanders.</strong>
            Matheson GO, Allen PS, Ellinger DC, Hanstock CC, Gheorghiu D, McKenzie DC, Stanley C, Parkhouse WS,
            Hochachka PW Sports Medicine Division, University of British Columbia, Vancouver, Canada. Two metabolic
            features of altitude-adapted humans are the <strong>maximal O2 consumption (VO2max) paradox (higher work
                rates following acclimatization without increases in VO2max)
            </strong>and the lactate paradox (progressive reductions in muscle and blood lactate with exercise at
            increasing altitude). To
        </p>

        <p>
            J Hum Hypertens 1995 Feb;9(2):119-22.<strong>
                Pressor effect of hyperventilation in healthy subjects.</strong>Todd GP, Chadwick IG, Yeo WW, Jackson
            PR, Ramsay LE.
        </p>
        <p>
            J Infect Dis 1998 May;177(5):1418-21.<strong>The effect of lactic acid on mononuclear cell secretion of
                proinflammatory cytokines in response to group B streptococci.</strong>
            Steele PM, Augustine NH, Hill HR Department of Pathology, University of Utah School of Medicine, Salt Lake
            City 84132, USA.<strong><hr /></strong>
        </p>
        <p>
            J Appl Physiol 1994 Apr;76(4):1462-7<strong>.</strong> Lactic acidosis as a facilitator of oxyhemoglobin
            dissociation during exercise. Stringer W, Wasserman K, Casaburi R, Porszasz J, Maehara K, French W.
        </p>

        <p>
            <strong>Involvement of nitric oxide and N-methyl- D-aspartate in acute hypoxic altitude convulsion in mice.
            </strong>Chen CH; Chen AC; Liu HJ. Aviat Space Environ Med, 1997 Apr, 68:4, 296-9. "Altitude convulsion is a
            rather specific form of experimental convulsion which is induced by acute exposure to a hypobaric hypoxic
            condition. Several neurotransmitters have been shown to be involved in the mechanisms of altitude
            convulsions." "The novel neurotransmitter nitric oxide (NO) may be involved in the mechanisms of altitude
            convulsion through its neuronal signalling roles in relation to the NMDA receptor." <strong>"NO synthesis
                precursor, L-arginine (20, 40, 200, 800 mg/kg), resulted in a dose-dependent decrease in the ACT in
                mice, while the NO synthase (NOS) inhibitor, NG-nitro-L-arginine-methyl ester (L-NAME, 1.25, 2.50, 5.00
                mg/kg, i.p.) increased the ACT."</strong>
            "CONCLUSIONS: These findings suggest an important signalling role for nitric oxide and NMDA in the
            development of altitude convulsion and further support the hypothesized relationship between NMDA-receptor
            mediated neurotoxicity and nitric oxide."<strong> </strong>
        </p>
        <p>
            <strong>Excitotoxicity in the lung: N-methyl-D-aspartate- induced, nitric oxide-dependent, pulmonary edema
                is attenuated by vasoactive intestinal peptide and by inhibitors of poly(ADP-ribose) polymerase.
            </strong>
            Said SI; Berisha HI; Pakbaz H. Proc Natl Acad Sci U S A, 1996 May 14, 93:10, 4688-92. <strong>"Excitatory
                amino acid toxicity, resulting from overactivation of N-methyl-D-aspartate (NMDA) glutamate receptors,
                is a major mechanism of neuronal cell death in acute and chronic neurological diseases. We have
                investigated whether excitotoxicity may occur in peripheral organs, causing tissue injury, and report
                that NMDA receptor activation in perfused, ventilated rat lungs triggered acute injury, marked by
                increased pressures needed to ventilate and perfuse the lung, and by high-permeability edema."</strong>
            The injury was prevented by competitive NMDA receptor antagonists or by channel-blocker MK-801, and <strong
            >was reduced in the presence of Mg2+.</strong> As with NMDA toxicity to central neurons, the lung injury was
            nitric oxide (NO) dependent: it <strong>required L-arginine, was associated with increased production of
                NO,</strong> and was attenuated by either of two NO synthase inhibitors. The neuropeptide<strong>
            </strong>vasoactive intestinal peptide and<strong>
                inhibitors of poly(ADP-ribose) polymerase also prevented this injury, but without inhibiting NO
                synthesis, both acting by inhibiting a toxic action of NO that is critical to tissue injury.
            </strong>

            The findings indicate that: (i) NMDA receptors exist in the lung (and probably elsewhere outside the central
            nervous system), (ii) excessive activation of these receptors may provoke acute edematous lung injury as
            seen in the "adult respiratory distress syndrome," and (iii) this injury can be modulated by blockade of one
            of three critical steps: NMDA receptor binding, inhibition of NO synthesis, or activation of
            poly(ADP-ribose) polymerase.
        </p>
        <p>
            <strong>Adenosine modulates N-methyl-D- aspartate- stimulated hippocampal nitric oxide production in vivo.
            </strong>Bhardwaj A; Northington FJ; Koehler RC; Stiefel T; Hanley DF; Traystman RJ. Stroke, 1995 Sep, 26:9,
            1627-33. "Adenosine acts presynaptically to inhibit release of excitatory amino acids (EAAs) and is thus
            considered to be neuroprotective. Because EAA-stimulated synthesis of nitric oxide (NO) may play an
            important role in long-term potentiation and excitotoxic-mediated injury, we tested the hypotheses that
            adenosine agonists attenuate basal and EAA-induced NO production in the hippocampus in vivo and that
            adenosine A1 receptors mediate this response." "...these data are consistent with in vitro results showing
            that NMDA receptor stimulation enhances NO production. Furthermore, we conclude that stimulation of A1
            receptors can attenuate the basal as well as NMDA-induced production of NO. Because NMDA receptor
            stimulation amplifies glutamate release, our data are consistent with presynaptic A1 receptor-mediated
            inhibition of EAA release and consequent downregulation of NO production."
        </p>
        <p>
            Anesthesiology 1993 Jan;78(1):91-9.<strong>
                Hypocapnia worsens arterial blood oxygenation and increases VA/Q heterogeneity in canine pulmonary
                edema.</strong> Domino KB, Lu Y, Eisenstein BL, Hlastala MP. University of Washington Medical School,
            Seattle. "Hyperventilation frequently is employed to reduce carbon dioxide partial pressure in patients in
            the operating room and intensive care unit. However the effect of hypocapnia on oxygenation is complex and
            may result in worsening in patients with preexisting intrapulmonary shunt." "Both hypocapnia and hypercapnia
            were associated with an increased VA/Q inequality. However, PaO2 decreased and P[A-a]O2 increased with only
            hypocapnia. These results suggest that hyperventilation to reduce PaCO2 may be detrimental to arterial PO2
            in some patients with lung disease."
        </p>

        <p>
            <strong>Acta Anaesthesiol Scand 1996 Jan;40(1):133-4 Hyperlactatemia associated with hypocarbic
                hyperventilation. Cheung PY</strong>
        </p>
        <p>
            Am J Physiol 1999 May;276(5 Pt 1):E922-9 Hyperlactatemia reduces muscle glucose uptake and GLUT-4 mRNA while
            increasing (E1alpha)PDH gene expression in rat. Lombardi AM, Fabris R, Bassetto F, Serra R, Leturque A,
            Federspil G, Girard J, Vettor R Endocrine Metabolic Laboratory, Department of Medical and Surgical Sciences,
            University of Padova, 35100 Padova, Italy. <strong>
                An increased basal plasma lactate concentration is present in many physiological and pathological
                conditions, including obesity and diabetes. We previously demonstrated that acute lactate infusion in
                rats produced a decrease in overall glucose uptake.</strong>
            The present study was carried out to further investigate the effect of lactate on glucose transport and
            utilization in skeletal muscle. In chronically catheterized rats, a 24-h sodium lactate or bicarbonate
            infusion was performed. To study glucose uptake in muscle, a bolus of 2-deoxy-[3H]glucose was injected in
            basal condition and during euglycemic-hyperinsulinemic clamp. Our results show that hyperlactatemia
            decreased glucose uptake in muscles (i.e., red quadriceps; P &lt; 0.05). Moreover in red muscles, both
            GLUT-4 mRNA (-30% in red quadriceps and -60% in soleus; P &lt; 0.025) and protein (-40% in red quadriceps; P
            &lt; 0.05) were decreased, whereas the (E1alpha)pyruvate dehydrogenase (PDH) mRNA was increased (+40% in red
            quadriceps; P &lt; 0.001) in lactate-infused animals. PDH protein was also increased (4-fold in red
            gastrocnemius and 2-fold in red quadriceps). These results indicate that <strong>chronic
                hyperlactatemia</strong> reduces glucose uptake by affecting the expression of genes involved in glucose
            metabolism in muscle, suggesting a role for lactate in t<strong>he development of insulin
                resistance.</strong>
        </p>

        <p>
            Radiat Res 1993 Apr;134(1):79-85 <strong>Effects of in vivo heart irradiation on myocardial energy
                metabolism in rats.</strong>
            Franken NA, Hollaar L, Bosker FJ, van Ravels FJ, van der Laarse A, Wondergem J Department of Clinical
            Oncology, University Hospital, Leiden, The Netherlands. To investigate the effect of in vivo heart
            irradiation on myocardial energy metabolism, we measured myocardial adenosine nucleotide concentrations and
            mitochondrial oxygen consumption in left ventricular tissue of rats 0-16 months after local heart
            irradiation (20 Gy). At 24 h and 2 months no difference in myocardial adenosine nucleotide concentration was
            apparent between irradiated and control hearts. The total myocardial adenosine nucleotide concentrations in
            irradiated hearts compared to those of nonirradiated controls tended to be lower from 4 months onward. The
            rate of<strong>
                oxidative energy production (state 3 respiration) in irradiated hearts was significantly reduced ompared
                with that of age-matched controls from 2 months onward. Moreover, as a result of aging, time-dependent
                decrease in the rate of oxidative energy production was observed in both rradiated and control hearts
            </strong>
            <hr />
            <strong>changes in energy supplies provide a mechanism to explain impaired contractility after local heart
                irradiation.
            </strong>
        </p>
        <p>
            J Radiat Res (Tokyo) 1993 Sep;34(3):195-203.<strong>
                Radiosensitization of human lung fibroblasts by chemical that decrease ATP levels.
            </strong>Kumar A, Kimura H, Aoyama T.<strong>
                "Radiosensitization by lactate, pyruvate, nalidixic acid and novobiocin was studied in exponentially
                growing SH-18L human lung fibroblasts. All the chemicals had a slight radiosensitizing effect at a low
                concentration and a definite effect at a higher one." "Fibroblasts incubated with the low concentration
                of each chemical for 24 hrs after X irradiation showed no reduction in intracellular ATP content,
                whereas, the higher concentration produced a significant decrease.
            </strong>These observations suggest that the decrease in the ATP content may be involved in the
            radiosensitization of human fibroblasts at high concentrations of these chemicals.<strong>
                In contrast, radiosensitization at a low concentration is not explained by a relationship to ATP
                content. Different mechanisms may be involved in radiosensitization at low and high concentrations of
                these chemicals."</strong>
        </p>
        <p>
            J Exp Med 1993 May 1;177(5):1391-8. <strong>Enhancement of experimental metastasis by tumor necrosis
                factor.</strong> Orosz P, Echtenacher B, Falk W, Ruschoff J, Weber D, Mannel D.N. Institute for
            Immunology and Genetics, German Cancer Research Center, Heidelberg. "The influence of endogenous and
            exogenous tumor necrosis factor (TNF) on metastasis was investigated in an experimental fibrosarcoma
            metastasis model." "This effect was time dependent, as administration of rmTNF 5 h before or 1 h but not 24
            h after tumor cell inoculation caused an increase of tumor cell colony formation on the lung surface,
            suggesting an influence of TNF on the vascular adhesion and diapedesis of tumor cells. Since tumor-bearing
            mice showed an enhanced ability to produce TNF after endotoxin injection compared to control mice,
            tumor-bearing mice were treated with anti-mTNF antibodies. Neutralization of endogenous tumor-induced TNF
            led to a significant decrease of the number of pulmonary metastases. Histological analysis of
            micrometastases in the lung on day 5 by silver staining of proteins associated with nucleolar organizer
            regions revealed <strong>
                more metastatic foci and augmented proliferative activity of the tumor cells after
            </strong>
            <strong>rmTNF pretreatment of mice.</strong> However, no direct effect of rmTNF on the proliferation rate of
            tumor cells was seen in vitro."
        </p>
        <p>
            Nippon Geka Gakkai Zasshi 1996 Sep;97(9):726-32.<strong>
                [Energy substrate metabolism during stress].
            </strong> Sugimoto H. Department of Traumatology and Critical Care Medicine, Osaka University School of
            Medicine, Suita, Japan.<strong>
                "Energy substrate metabolism during stress is characterized by increased REE (resting energy
                expenditure), hyperglycemia, hyperlactatemia and protein catabolism. This stress-induced hypermetabolic
                responses are closely related to increased secretion of neurohormonal and cytokine mediators. The
                insulin resistance hyperglycemia has been called "stress diabetes" or 'surgical diabetes.' Glucose
                disposal has been thought to be impaired in this condition." "This hyperglycemia in stress diabetes
                results from a postreceptor mechanism. Stress hyperlactatemia is thought to be caused by decreased
                pyruvate dehydrogenase activity rather than tissue hypoperfusion."</strong>
        </p>
        <p>
            <em>Clin Physiol 1995 Nov;15(6):581-95.
            </em>
            <strong><em>Effects of lactate infusion on hepatic gluconeogenesis and glycogenolysis.</em></strong>
            <em>
                Haesler E, Schneiter P, Temler E, Jequier E, Tappy L.</em>
        </p>
        <p>
            <em>Cancer Res 1993 Apr. 15;53(8):1939-44..
            </em>
            <strong><em>Tumor necrosis factor alpha as an autocrine and paracrine growth factor for ovarian cancer:
                    monokine induction of tumor cell proliferation and tumor necrosis factor alpha expression.</em
                ></strong>
            <em>
                Wu S, Boyer CM, Whitaker RS, Berchuck A, Wiener JR, Weinberg JB, Bast RC Jr.</em>
        </p>
        <p>
            Klin Med (Mosk) 1989 May;67(5):38-41<strong>. ["Dry" carbon dioxide baths in treating patients with
                myocardial infarction at the sanatorium stage of rehabilitation].
            </strong>

            [Article in Russian] Barashkova NL, Kartamysheva NL, Krasnova VP, Kriuchkova LN, Miasoedova E.S. A group of
            75 patients with a history of myocardial infarction and repeated myocardial infarction were subjected to
            treatment involving dry carbon dioxide baths. Its results demonstrated normalization of IHD manifestations,
            such as coronary and heart failure, functional state of the cardiovascular system, its reserve
            potentialities and adaptation to physical effort. Under the influence of a course treatment with dry carbon
            dioxide baths hemodynamic parameters of cardiac output (cardiac and stroke volume) underwent favourable
            changes, rhythm slowed down, diastole became longer and systolic and diastolic arterial pressure decreased.
            The data obtained substantiate application of dry carbon dioxide baths in the recovery period to I-III
            functional classes patients with a history of myocardial infarction.
        </p>
        <p>
            J Dev Physiol 1989 Nov;12(5):283-6. <strong>Haemodynamic effects of respiratory alkalosis independent of
                changes in airway pressure in anaesthetized newborn dogs.</strong> Reuter JH, Donovan EF, Kotagal U.R.
            <strong>"We have recently reported a decrease in cardiac output in newborn dogs during respiratory alkalosis
                which is independent of changes in airway pressure."</strong>
        </p>
        <p>
            Undersea Hyperb Med 1994 Jun;21(2):169-83. <strong>Influence of hyperbaric oxygen on left ventricular
                contractility, total coronary blood flow, and myocardial oxygen consumption in the conscious dog.
            </strong>
            Savitt MA, Rankin JS, Elberry JR, Owen CH, Camporesi E.M. <strong>"It is known that hyperbaric oxygenation
                (HBO) decreases total coronary blood flow (TCBF) and cardiac output (CO)."</strong>
        </p>
        <p>
            <strong><em>Heart rhythm disturbances in the inhabitants of mountainous regions.</em></strong>
            <em>
                Mirrakhimov MM; Meimanaliev TS Cor Vasa, 1981, 23:5, 359-65.
            </em>
            <strong><em>"During exercise heart arrhythmias</em></strong>
            <strong><em>
                    appeared conspicuously less frequently in the high mountain than in the low altitude inhabitants."
                </em></strong>
        </p>
        <p>© Ray Peat 2006. All Rights Reserved. www.RayPeat.com</p>
    </body>
</html>