Changes in energetic metabolism of rat myocardium during acclimation to high altitude

The results reported in this paper refer to the modifications of energetic equilibrium in the myocardium tissue, involved by altitude chronic hypoxia. Experiments have been done on adult rats (males and females) placed in the Jungfraujoch station, in the Alps, at 3,500 m. The obtained data were compared to control animals, bred in Geneva. On the first days of stay at high altitude, a significant fall of tissue energy charge, due to the non-modified enzyme levels in comparison with the controls, was observed. After several weeks of stay in chronic hypoxia, the metabolic modifications leading to the improvement of energy production and to the achievement of a new equilibrium state, take place. In acclimatized animals some good correlation, between the energy charge and the activity of glycolytic enzymes (PGK and PK) ensuring the ATP generation, is established.