Resumen

TORRES, SH; FINOL, HJ; BRITO, A  y  RIVERA, H. Alteraciones musculares en montañistas que ascendieron a Los Himalayas. RFM [online]. 2002, vol.25, n.1, pp.41-44. ISSN 0798-0469.

Skeletal muscle needle biopsies were obtained from quadriceps femoris muscle in five venezuelan climbers, two months before, and in four of the subjects, one month after an expedition to the Himalayas Mountains. In the samples, fibre types were determined by the miofibrillar adenosin triphosphatase reaction, and capillaries were stained with the a-amylase-PAS reaction. Part of each sample was processed for ultrastructural study. The climbers performance was related to the previous state of the muscle. The three subjects that reached the goal of 7100 m altitude were those with normal of slightly altered muscles in the biopsy before the expedition. One month after the descent, muscle showed segmental alterations manifested as atrophy, capillary damage and infiltration of macrophages. No change was found in muscle fibre proportions. It is concluded that performance of the climbers depends on the previous state of skeletal muscle, and that the combined effect of altitude, exercise and cold produced segmental damage in skeletal muscle.

Palabras clave : Hypoxia; Exercise; Skeletal muscle; Atrophy; Climbing.