The effects of chronic ethanol treatment on oligomycin sensitive ATPase activity in the guinea pig heart

In an effort to determine the effect of chronic ethanol ingestion on myocardial oligomycin sensitive ATPase, guinea pigs were fed 15% ethanol instead of drinking water for 34 weeks. Mg2+-ATPase activity of isolated mitochondria was determined in control and alcohol fed guinea pigs at 16, 20, 24 and 34 weeks. To prove a possible higher fragility of the mitochondria from alcohol fed animals, the ATPase activity was also determined in the supernatant after the isolation of mitochondria "100 000 g fraction". Mg2+-ATPase activity of the isolated mitochondria was time dependent reduced to 56% of the value obtained in the control animals. In the "100 000 g fraction" the ATPase activity, however, started to increase after 8 weeks and after 34 weeks it was about twice as high than in the control group. The findings of this study document a decrease in oligomycin sensitive ATPase activity and an increase in mitochondrial fragility after chronic ethanol ingestion. It supports in the thesis that chronic alcohol intake affects the activity of the intrinsic membrane enzymes by structural derangements of mitochondrial membrane. The changes may play a role in the development of alcoholic cardiomyopathy.