II. Morphological Adaptations of Human Skeletal Muscle to Chronic Hypoxia*
| Autor: | S. R. Kayar, H. Howald, H. Claassen, Paolo Cerretelli, C. Schlegel, E. Kleinert, Hans-Heinrich Hoppeler |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Adult
Male medicine.medical_specialty Acclimatization Physical Therapy Sports Therapy and Rehabilitation Stereology Mitochondrion Thigh Internal medicine medicine Humans Orthopedics and Sports Medicine Hypoxia Chemistry Catabolism Altitude Muscles Skeletal muscle Anatomy Effects of high altitude on humans Hypoxia (medical) Capillaries Mountaineering Endocrinology medicine.anatomical_structure Chronic Disease Body Composition medicine.symptom Myofibril |
| Zdroj: | International Journal of Sports Medicine. 11:S3-S9 |
| ISSN: | 1439-3964 0172-4622 |
| DOI: | 10.1055/s-2007-1024846 |
| Popis: | Muscle structural changes during typical mountaineering expeditions to the Himalayas were assessed by taking muscle biopsies from 14 mountaineers before and after their sojourn at high altitude (greater than 5000 m for over 8 weeks). M. vastus lateralis samples were analyzed morphometrically from electron micrographs. A significant reduction (-10%) of muscle cross-sectional area was found on CT scans of the thigh. Morphologically this loss in muscle mass appeared as a decrease in muscle fiber size mainly due to a loss of myofibrillar proteins. A loss of muscle oxidative capacity was also evident, as indicated by a decrease in the volume of muscle mitochondria (-25%). In contrast, the capillary network was mostly spared from catabolism. It is therefore concluded that oxygen availability to muscle mitochondria after prolonged high-altitude exposure in humans is improved due to an unchanged capillary network, supplying a reduced muscle oxidative capacity. |
| Databáze: | OpenAIRE |
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