Male, female and castrated rats, three wk of age, were fed a
low-fat diet for 14 wk followed by high-fat diets (20% by weight) for one wk containing graded levels of
erucic acid from 1 to 50%, to evaluate the effect of short-term feeding and interaction of male
sex hormones on formation of heart lesions. Some rats within each group were returned to the
low-fat diet for one wk after the test period. For comparison, one group of three-wk-old male rats was fed the high fat 50%
erucic acid diet for 15 wk.
Erucic acid depressed growth rate and food consumption and increased cardiac
lipidosis and
triglycerides proportional to the
erucic acid content of the diet. There were no sex differences, and the effects disappeared once rats were returned to the
low-fat diet for one week. There was a significance (P less than 0.05) in the incidence of myocardial
necrosis among male rats fed increased levels of
erucic acid for one week, but the response was not linear to the increase in dietary
erucic acid. Furthermore, the response was much less than in males fed the 50%
erucic acid diet continually for 15 weeks. These results suggest that the short-term model is not a suitable substitute for the long-term feeding trial to test the cardiopathogenicity of a
vegetable oil. The significantly lower incidence in myocardial lesions in female and castrated male rats compared with male rats suggests involvement of
sex hormones.(ABSTRACT TRUNCATED AT 250 WORDS)