Biochemical and pathological changes in rats fed low dietary levels of brominated cottonseed oil

Groups of eight male rats were fed semi-purified diets containing 0·0, 0·02, 0·1 or 0·5% brominated cottonseed oil for 120 days. Total food consumption and body-weight gains were similar for all groups. Animals fed 0·5% but not those fed 0·1 or 0·02% brominated oil had increased relative heart and liver weights, which were a reflection of fat accumulation in these organs. Myocarditis was present in about 85% of animals fed 0·5% brominated oil and microfollicular hyperplasia of the thyroid was seen occasionally in animals of this group. Decreased hepatic activity of glucose 6-phosphate dehydrogenase was noted in animals fed 0·1 or 0·5% brominated oil but no changes were detected in isocitric dehydrogenase activity or in hepatic drug-metabolizing capacity in animals treated with brominated oil.