The effects of ethanol on myocardial mitochondrial and sarcoplasmic ATPase in rats

The effects of the ethanol on the activities of mitochondrial and sarcoplasmic Mg2+-Ca2+-activated ATPase in rat myocardium were studied on two experimental alcoholic models: a) in an acute model - after a single dose of ethanol, 250 mg/100g of body weight; b) in a chronic model - after daily administration of the same dose for 10 weeks. In the acute model the ATPase activities sank both in mitochondria and sarcoplasmic reticulum. In the chronic model an opposite tendency was observed: in both subcellular organelles the ATPase activities moderately rose. The findings are assessed from the aspect of the dynamics of myocardial metabolic changes in dependence on the duration of action of ethanol upon the myocardium. It is stressed that acute symptoms of the ethanol action on myocardial metabolic processes are no adequate basis for drawing conclusions about the mechanism of myocardial lesion and the development of ethanol-induced mycardiopathy in chronic alcoholics.