Biochemical and pathological changes in rats fed brominated cottonseed oil for 80 days

Groups of male rats were fed semi-purified diets containing 0·0, 0·5 or 2·5%brominated cottonseed oil for 80 days. Growth retardation and impaired food utilization were observed in the 2·5% group, in which there was evidence of a slight anaemia. Enlargement of the heart occurred at the 0·5·5 % level and of the liver, heart, kidneys and spleen at the 2·5% level. All rats fed the brominated oil displayed thyroid hyperplasia, myocarditis, fatty change in the liver, arrested testicular development, vacuolation of the renal tubular epithelium and reduced liver glucose 6-phosphatase and glucose 6-phosphate dehydrogenase activities, the changes being less marked at the 0·5 than at the 2·5 % level. Work is in progress to establish a no-effect level for brominated cottonseed oil in the diet of rats.