Deposition of fat in the liver and carcass of the rat on diets high in fat and low in lipotropic factors

Abstract

Six groups of rats were fed for 14 days on diets in which the common basal constituents were fat-free and of low choline content. Each diet contained in addition 40% of one of the following fats: beef dripping, butter, olive oil, cod liver oil, coconut oil and palm oil. The fatty acids of the pooled carcasses were subjected to a detailed analysis and the findings are compared with those of Channon and Wilkinson [1936] on the liver acids of the same animals. Further, a group of 72 animals was fed on the coconut oil diet for 21 days and the fatty acids of the livers compared with those of the carcasses. Intense fatty livers resulted, varying from 30.7% in the case of the butter fat to 7.2% of the fresh liver weight for the cod liver oil, but no relationship was found to exist between the amount of fat in the livers and that in the carcasses. The saturated acids of the liver glycerides were found to resemble closely those of the carcass both in the proportion of the total fatty acids and in their mean molecular weights, while the unsaturated acids were less closely related. The liver phosphatide acids showed no relationship with the carcass fatty acids. The effects of the various dietary fats on the amounts of the individual constituent acids of the carcass fats were very marked and are discussed in detail. If desaturation of lower acids takes place, the products are not stored to any measurable extent either in the liver or in the carcass.