Nutritional Fatty Livers in Rats

Abstract

Dietary deficiencies of choline, essential amino acids, essential fatty acids and inositol can under certain conditions give rise to an accumulation of liver fat. A dietary deficiency of choline can be very largely, if not completely, alleviated by providing in the diet sources of labile methyl groups, such as betaine or methionine, which permit choline synthesis in the body. Also, choline deficiency is made less severe if folic acid and vitamin B¹², which are involved in the synthesis of ethanolamine and methyl groups, are included in the diet. The fatty liver induced by the feeding of low-protein diets which contain choline appears in some cases to be the result of a specific amino acid deficiency which may be induced by an amino acid imbalance. It appears to be influenced as well, however, by the over-all level of dietary protein and by the levels of certain dispensible amino acids, relationships which require further study. Although many of the nutritional interrelationships that influence the production of fatty livers have been worked out, and although a number of changes in the rates of metabolic reactions and in the levels of metabolically important compounds have been observed in the livers of rats fed on diets deficient in choline or essential amino acids, an integrated picture of the mechanisms responsible for the production of fatty livers has not, as yet, been obtained.