[Adaptation and disadaptation of the myocardium of rats trained to hypoxia].

Adaptation to oxygen deficit resulted from training of rats to hypoxia (8--9% O2) at the normal atmospheric pressure, during 3 weeks. Subsequent 2-week training decreased the resistance to hypoxia (disadaptation). Perfusion of the isolated hearts of adapted and disadapted animals at anoxic regimen together with the recording of the systolic pressure in the left ventricle, the rhythm, glucose uptake, lactate excretion, coronary blood flow, and the histochemical data on SDH, MDH, LDH, and hydroxibutyric DH, as well as the electron microscopy of the left ventricle mitochondria, indicate that the range of compensation reactions increases in adapted rats and decreases in disadapted ones.