Pre-adaptation, adaptation and de-adaptation to high altitude in humans: cardio-ventilatory and haematological changes
| Autor: | Nathalie Garcia, Yves Besnard, Anne-Marie Hanniquet, Angélique Guinet, Gustave Savourey, Jacques Bittel |
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| Rok vydání: | 1996 |
| Předmět: |
Adult
Male medicine.medical_specialty Physiology Hematocrit Tibet Acclimatization Nepal Reticulocyte Count Heart Rate Physiology (medical) Internal medicine Respiration Heart rate medicine Humans Orthopedics and Sports Medicine Hypoxia Erythropoietin Exercise Hematologic Tests medicine.diagnostic_test business.industry Altitude Public Health Environmental and Occupational Health Heart General Medicine Hypoxia (medical) Effects of high altitude on humans Adaptation Physiological Surgery Endocrinology Erythrocyte Count Arterial blood medicine.symptom business medicine.drug |
| Zdroj: | European journal of applied physiology and occupational physiology. 73(6) |
| ISSN: | 0301-5548 |
| Popis: | The aim of this study was first to investigate cardio-ventilatory and haematological responses induced by intermittent acclimation and second to study de-adaptation from high altitude observed after descent. To achieve these objectives nine subjects were submitted to intermittent acclimation in a low barometric chamber (8 h daily for 5 days, day 1 at 4500 m, day 5 at 8500 m) before an expedition to the Himalayas. Cardio-ventilatory changes were measured during a hypobaric poikilocapnic hypoxic test (4500 m, barometric pressure = 589 hPa) and haematological changes were studied at sea level. These measurements were performed before and after acclimation, after return to sea level, but also 1 and 2 months after the expedition. In addition, partial pressures of oxygen and carbon dioxide in arterial blood (PaO2, PaCO2) and arterial erythropoietin concentration [EPO] were measured at rest during the hypoxic test. Results suggested the pre-adaptation protocol was efficient since an increased PaO2 (+12%, P < 0.05), a smaller difference in alveolo-arterial PO2 ( -63%, P < 0.05) and a lower PaCO2 ( -11%, P < 0.05), subsequent to ventilatory changes, were observed after acclimation with a significant increase in reticulocytes and in sea level [EPO] (+44% and +62% respectively, P < 0.05). De-adaptation was characterized by a loss of these cardio-ventilatory changes 1 month after descent, whereas the haematological changes (increased red blood cells and packed cell volume, P < 0.05) persisted for 1 month before disappearing 2 months after descent. This study would also suggest that acute hypoxia performed after a sojourn at high altitude could induce significantly depressed EPO responses (P < 0.05). |
| Databáze: | OpenAIRE |
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