[Functional morphology of myocardial ultrastructure during prolonged adaptation to pressure chamber hypoxia].

The myocardium of the right and left heart ventricles of rats was studied during 2.5-month adaptation to high-pressure chamber hypoxia (at an altitude of 6000 m). During varying time of rats' adaptation to hypoxia, destructive and compensatory-adaptive processes in the cardiomyocytes were seen concurrently. In long-term adaptation to high-pressure chamber hypoxia there developed hypertrophy largely of the heart right ventricle on account of hyperplasia and hypertrophy of individual intracellular organelles, particularly of mitochondria. The animals who adapted to high-pressure chamber hypoxia showed enhanced metabolic processes in the myocardium.