Abstract des Autors

The Italian contribution to the study of structural, ultrastructural and chemical characteristics (studied by NMR spectroscopy and imaging) of the muscle under various conditions of physical and environmental stress is summarized. In particular, the results of the experiments carried out in sea level and high altitude natives (Sherpas, Tibetans and Andeans) in conditions of chronic hypoxia are analyzed in respect to changes in muscle mass, fibre types, mitochondrial volume density and certain enzymatic activities of some respiratory chain and glycolytic pathway enzymes. It is hypothesized that certain changes of skeletal muscle of Himalayan and Andean populations are the result of genetic changes since they are also present in second generation of individuals living at lower altitudes. Verf.-Referat