Ultrastructure of rat myocardium after feeding a diet with low--erucic acid rapeseed oil.

Electron microscopy was applied to study the myocardium of rats fed a diet with sunflower oil (group I), low-erucic acid rapeseed oil (group II), or high-erucic acid rapeseed oil (group III). The most severe lesions were found in group III. The rats fed sunflower oil showed slight lesions in the form of dilated channels of endoplasmic reticulum and the presence of a few lipid droplets. Similar abnormalities were found in group II, they were followed, however, after four and eight weeks of experiment by considerable mitochondriosis with compression and atrophy of sarcomeres. In group III considerable myocardial fatty degeneration (numerous lipid vacuoles) was found already after the first week of experiment, after four and eight weeks, however, the number of lipid vacuoles gradually decreased with time. Like group II group III showed considerable mitochondriosis with atrophy of contractile elements.