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Testing a short‐term feeding trial to assess compositional and histopathological changes in hearts of rats fed vegetable oils
Author(s) -
Kramer J. K. G.,
Farnworth E. R.,
Thompson B. K.,
Corner A. H.
Publication year - 1988
Publication title -
lipids
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.601
H-Index - 120
eISSN - 1558-9307
pISSN - 0024-4201
DOI - 10.1007/bf02535458
Subject(s) - erucic acid , lipidology , clinical chemistry , medicine , zoology , endocrinology , biology , rapeseed , food science
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<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. However, the process appears to be long term, since changes in cardiac lipids and their fatty acid pattern between sexes became evident after one wk on diet but was significant only after long‐term feeding.