Different changes in the cytosole creatine kinase isoenzymes from heart of adult and old rats during stress

We have shown that immobilization stress causes changes in the spectrum of the heart’s cytosole creatine kinase isoenzymes. In myocardium adult immobilized rats, MM isoenzyme is decreased and MB and BB isoenzymes are increased compared to intact animals. The pattern of isoenzyme response in old and adult rats was different. Immobilization of old rat caused an increase of MM and a decrease of MB isoenzyme in the heart’s creatine kinase isoenzyme spectrum. We suggest that this change in the creatine kinase isoenzyme spectrum in the myocardium of adult rats plays an adaptive role, increasing the effectiveness of its performance during stress. In old rats, apparent changes in the creatine kinase isoenzyme spectrum promote a disturbance of myocardial energy metabolism.