Decreased 1,2-diacylglycerol levels in myopathic hamster hearts during the development of heart failure.

1,2-Diacylglycerol is believed to play an important role in cellular functions through protein kinase C activation, although its role in cardiac functions remains largely unexplored. We determined the level of 1,2-diacylglycerol and its fatty acid composition in heart tissues from Syrian hamsters with hereditary cardiomyopathy (BIO 14.6 strain) during the development of congestive heart failure from 90 days to 240 days of age. The myopathic hamsters had lower contents of triglyceride and of the major phospholipids, phosphatidylcholine, phosphatidylethanolamine and cardiolipin, in the myocardium when compared to normal hamsters, whereas there was no difference in the cholesterol content. No difference in the myocardial 1,2-diacylglycerol content was observed at 90 days of age. On the other hand, 1,2-diacylglycerol contents in myopathic hearts at 160 and 240 days of age were significantly lower by 21% and 52%, respectively, then in age-matched normal hamsters. The oldest hamsters (240-day-old) showed reduced 1,2-diacylglycerol levels in both groups despite an age-related increase in most lipids. The 1,2-diacylglycerol fatty acid composition profile was found to be different from that of other lipids, and there were several differences in the fatty acid composition of 1,2-diacylglycerol between the two groups at 240 days of age. These results indicate that decreased levels of 1,2-diacylglycerol occur concomitantly with congestive heart failure in the myopathic hamsters.