Myocardial metabolism at different environmental temperatures in experimental myocardial necrosis.

Although the effect of cold and heat stress on myocardial metabolisms has been widely studied, this parameter has not been investigated over a wide range of environmental temperatures after myocardial infarction. Since high as well as low temperatures are known to adversely affect the myocardium, changes in enviromental temperature are likely to be of great importance to patients suffering from acute coronary insult. Therefore, the myocardial metabolism was studied at different environmental temperatures in albino rats with isoproterenol-induced infarct-like myocardial necrosis. Male albino rats weighing 100 to 150 g were selected for the study. The investigations included ECG (lead II), histology, serum free fatty acids (FFA), serum triglycerides (TGS), cardiac noradrenaline, cardiac glycogen, and adrenal ascorbic acid, after the induction of myocardial necrosis. The biochemical changes were minimum between 10 and 15 degrees C while, at 4 degrees C, marked changes were observed. No significant change was seen in the serum triglycerides.