Myoglobin content and enzymatic activity of muscle and altitude adaptation

1962 ◽  
Vol 17 (2) ◽  
pp. 301-305 ◽  
Author(s):  
Baltazar Reynafarje
Keyword(s):  
Cytochrome C ◽  
Enzymatic Activity ◽  
High Altitude ◽  
Sea Level ◽  
Human Subjects ◽  
Reduced Form ◽  
Sartorius Muscle ◽  
Healthy Human ◽  
Altitude Adaptation ◽  
Made In

Quantitative determinations of myoglobin were made in the sartorius muscle of healthy human subjects native to sea level and high altitude. The specific activities of the reduced form of diphosphopyridine nucleotide oxidase (DPNH-oxidase), DPNH- and the reduced form of triphosphopyridine nucleotide (TPNH)-cytochrome c reductases, transhydrogenase, and isocitric and lactic dehydrogenases were also examined. There was found a significantly higher myoglobin concentration in the muscle of the high-altitude native as compared with the sea-level resident. The enzyme systems DPNH-oxidase, TPNH-cytochrome c reductase, and transhydrogenase similarly showed a significantly higher activity in the altitude resident. It was concluded that the respiratory capacity of the muscle was apparently higher in the altitude native than in the sea-level one. The enhanced enzymatic activity was probably related to the higher pigment content of the skeletal muscle. Results on myoglobin determinations in several other muscles from certain sea-level patients are discussed. Submitted on July 24, 1961

Carotid baroreflex control of heart rate during acute exposure to simulated altitudes of 3,800 m and 4,300 m

1997 ◽  
Vol 273 (4) ◽  
pp. R1219-R1223 ◽  
Author(s):  
S. Sagawa ◽  
R. Torii ◽  
K. Nagaya ◽  
F. Wada ◽  
Y. Endo ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Logistic Function ◽  
Cardiac Response ◽  
Baroreflex Control ◽  
Carotid Baroreflex ◽  
Maximal Gain ◽  
Neck Chamber ◽  
Male Subjects ◽  
Made In

To examine the baroreflex response in humans during acute high-altitude exposure, the carotid baroreflex cardiac responsiveness was studied using a neck chamber in seven unacclimatized male subjects. Measurements were made in a high-altitude chamber on separate days at sea level and during 1-h exposure at two different altitudes of 3,800 m [partial pressure of oxygen in inspired air (Pi O2 ) = 90 mmHg] and 4,300 m (Pi O2  = 82 mmHg). R-R intervals were plotted against neck chamber pressures, and the baroreceptor response was analyzed by applying a four-parameter sigmoidal logistic function. The baroreceptor response curve shifted downward in either altitude, reflecting a tachycardic response at high altitude, and the magnitude of the shift was greater at 4,300 m than at 3,800 m. There was no change in the sigmoidal parameters at 3,800 m compared with sea level except for a reduction ( P < 0.05) of the minimum R-R interval. At 4,300 m the maximal R-R range, slope coefficient, minimum R-R interval, and maximal gain of the curve decreased significantly ( P < 0.05) compared with sea level values, whereas the centering point of the curve remained unchanged. These results suggest that hypoxia (Pi O2  = 82 mmHg) reduces the sensitivity of carotid baroreflex cardiac response.

High-altitude adaptation and maximum work performance

1984 ◽  
Vol 246 (4) ◽  
pp. R619-R623
Author(s):  
E. S. Johnson ◽  
C. A. Finch
Keyword(s):  
Beneficial Effect ◽  
High Altitude ◽  
Sea Level ◽  
Carrying Capacity ◽  
Work Performance ◽  
Work Capacity ◽  
Hypobaric Chamber ◽  
Altitude Adaptation ◽  
Maximum Work ◽  
Positive Effect

The treadmill work performance of rats at sea level with normal or elevated hematocrits was compared with that of rats conditioned in a hypobaric chamber at 450 Torr for 3 wk with similar hematocrit adjustments. A mean increase in hematocrit to 62 significantly improved the work performance of rats at sea level and at ambient O2 tensions of 100, 75, and 35 Torr. By contrast, rats conditioned in a hypobaric chamber with mean hematocrits of 40 and 58 performed similarly at all O2 tensions compared with sea-level rats with hematocrits of 43. Thus, although an increase in O2-carrying capacity of the blood of sea-level animals increased work capacity, altitude adaptation did not appear to result in any positive effect on work capacity, and indeed, seemed to interfere with the beneficial effect of polycythemia on maximum work performance.

scholarly journals Molecular Evolution of Cytochrome c Oxidase Underlies High-Altitude Adaptation in the Bar-Headed Goose

2010 ◽  
Vol 28 (1) ◽  
pp. 351-363 ◽  
Author(s):  
G. R. Scott ◽  
P. M. Schulte ◽  
S. Egginton ◽  
A. L. M. Scott ◽  
J. G. Richards ◽  
...  
Keyword(s):  
Molecular Evolution ◽  
Cytochrome C ◽  
High Altitude ◽  
Cytochrome C Oxidase ◽  
High Altitude Adaptation ◽  
Altitude Adaptation

scholarly journals High-altitude exposure of three weeks duration increases lung diffusing capacity in humans

2011 ◽  
Vol 110 (6) ◽  
pp. 1564-1571 ◽  
Author(s):  
Piergiuseppe Agostoni ◽  
Erik R. Swenson ◽  
Maurizio Bussotti ◽  
Miriam Revera ◽  
Paolo Meriggi ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Diffusing Capacity ◽  
Membrane Diffusion ◽  
Alveolar Volume ◽  
Pulmonary Capillary ◽  
Capillary Blood Volume ◽  
Pulmonary Capillary Blood ◽  
Altitude Adaptation ◽  
Alveolar Capillary

Background: high-altitude adaptation leads to progressive increase in arterial PaO2. In addition to increased ventilation, better arterial oxygenation may reflect improvements in lung gas exchange. Previous investigations reveal alterations at the alveolar-capillary barrier indicative of decreased resistance to gas exchange with prolonged hypoxia adaptation, but how quickly this occurs is unknown. Carbon monoxide lung diffusing capacity and its major determinants, hemoglobin, alveolar volume, pulmonary capillary blood volume, and alveolar-capillary membrane diffusion, have never been examined with early high-altitude adaptation. Methods and Results: lung diffusion was measured in 33 healthy lowlanders at sea level (Milan, Italy) and at Mount Everest South Base Camp (5,400 m) after a 9-day trek and 2-wk residence at 5,400 m. Measurements were adjusted for hemoglobin and inspired oxygen. Subjects with mountain sickness were excluded. After 2 wk at 5,400 m, hemoglobin oxygen saturation increased from 77.2 ± 6.0 to 85.3 ± 3.6%. Compared with sea level, there were increases in hemoglobin, lung diffusing capacity, membrane diffusion, and alveolar volume from 14.2 ± 1.2 to 17.2 ± 1.8 g/dl ( P < 0.01), from 23.6 ± 4.4 to 25.1 ± 5.3 ml·min−1·mmHg−1 ( P < 0.0303), 63 ± 34 to 102 ± 65 ml·min−1·mmHg−1 ( P < 0.01), and 5.6 ± 1.0 to 6.3 ± 1.1 liters ( P < 0.01), respectively. Pulmonary capillary blood volume was unchanged. Membrane diffusion normalized for alveolar volume was 10.9 ± 5.2 at sea level rising to 16.0 ± 9.2 ml·min−1·mmHg−1·l−1 ( P < 0.01) at 5,400 m. Conclusions: at high altitude, lung diffusing capacity improves with acclimatization due to increases of hemoglobin, alveolar volume, and membrane diffusion. Reduction in alveolar-capillary barrier resistance is possibly mediated by an increase of sympathetic tone and can develop in 3 wk.

Variability of oxygen affinity of blood: human subjects native to high altitude

1981 ◽  
Vol 51 (6) ◽  
pp. 1411-1416 ◽  
Author(s):  
R. M. Winslow ◽  
C. C. Monge ◽  
N. J. Statham ◽  
C. G. Gibson ◽  
S. Charache ◽  
...  
Keyword(s):  
High Altitude ◽  
Sea Level ◽  
Human Subjects ◽  
Oxygen Affinity ◽  
Respiratory Alkalosis ◽  
Red Cell ◽  
Acid Base ◽  
Constant Ph ◽  
Acid Base Status ◽  
Adverse Environmental Conditions

Whole blood O2 equilibrium curves (OEC) were measured in 46 Peruvians native to high altitude (4,540 m) and in 25 sea-level controls. A method was employed that records the entire OEC from 0 to 150 Torr with constant pH and PCO2. The data were analyzed by fitting the Adair equation describing the successive oxygenation of hemoglobin. At pH 7.4 the PO2 at which hemoglobin is half-saturated with O2 (P50) was significantly higher in the high-altitude population (31.2 +/- 1.9 Torr) than in controls (29.2 +/- 1.8 Torr, P less than 0.001). The acid-base status of the high-altitude subjects, however, was that of compensated respiratory alkalosis (plasma pH 7.439 +/- 0.065), and when the P50's were corrected to the subjects' plasma pH the values (30.1 +/- 2.2 Torr) could no longer be distinguished from the controls. We conclude that, on the average, increased P50 resulting from increased red cell 2,3-diphosphyoglycerate concentration at high altitude is offset by compensated respiratory alkalosis with the net result that the position of the OEC more closely approaches that of sea-level humans than has hitherto been thought. Considerable variation exists in P50, both at sea level and high altitude. This variation might have important consequences for acclimatization and survival under adverse environmental conditions.

Minimizing Carry-Over Effects After Treatment Failure and Maximizing Therapeutic Outcome

2014 ◽  
Vol 222 (3) ◽  
pp. 171-178 ◽  
Author(s):  
Mareile Hofmann ◽  
Nathalie Wrobel ◽  
Simon Kessner ◽  
Ulrike Bingel
Keyword(s):  
Treatment Failure ◽  
Human Subjects ◽  
Subsequent Treatment ◽  
Clinical Samples ◽  
Administration Route ◽  
Healthy Human ◽  
Negative Experiences ◽  
Analgesic Treatment ◽  
Balanced Design ◽  
Carry Over

According to experimental and clinical evidence, the experiences of previous treatments are carried over to different therapeutic approaches and impair the outcome of subsequent treatments. In this behavioral pilot study we used a change in administration route to investigate whether the effect of prior treatment experience on a subsequent treatment depends on the similarity of both treatments. We experimentally induced positive or negative experiences with a topical analgesic treatment in two groups of healthy human subjects. Subsequently, we compared responses to a second, unrelated and systemic analgesic treatment between both the positive and negative group. We found that there was no difference in the analgesic response to the second treatment between the two groups. Our data indicate that a change in administration route might reduce the influence of treatment history and therefore be a way to reduce negative carry-over effects after treatment failure. Future studies will have to validate these findings in a fully balanced design including larger, clinical samples.

Detection of Soluble Fibrin Monomer Complexes in Blood by Means of Protamine Sulphate Test

1968 ◽  
Vol 20 (01/02) ◽  
pp. 044-049 ◽  
Author(s):  
B Lipiński ◽  
K Worowski
Keyword(s):  
Human Subjects ◽  
Coronary Thrombosis ◽  
Mean Value ◽  
Healthy Human ◽  
Protamine Sulphate ◽  
Soluble Fibrin ◽  
Fibrin Monomer ◽  
Dog Plasma ◽  
The Mean ◽  
Precipitable Protein

SummaryIn the present paper described is a simple test for detecting soluble fibrin monomer complexes (SFMC) in blood. The test consists in mixing 1% protamine sulphate with diluted oxalated plasma or serum and reading the optical density at 6190 Å. In experiments with dog plasma, enriched with soluble fibrin complexes, it was shown that OD read in PS test is proportional to the amount of fibrin recovered from the precipitate. It was found that SFMC level in plasma increases in rabbits infused intravenously with thrombin and decreases after injection of plasmin with streptokinase. In both cases PS precipitable protein in serum is elevated indicating enhanced fibrinolysis. In healthy human subjects the mean value of OD readings in plasma and sera were found to be 0.30 and 0.11, while in patients with coronary thrombosis they are 0.64 and 0.05 respectively. The origin of SFMC in circulation under physiological and pathological conditions is discussed.

Chronic stress decreases circulating endocannabinoid 2-arachidonoylglycerol in healthy human subjects

2015 ◽  
Author(s):  
Buqing Yi ◽  
Igor Nichiporuk ◽  
Matthias Feuerecker ◽  
Gustav Schelling ◽  
Alexander Chouker
Keyword(s):  
Chronic Stress ◽  
Human Subjects ◽  
Healthy Human ◽  
Healthy Human Subjects
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