Choline Metabolism

Abstract

Supplementary cystine (0.1 to 0.2%) or methionine improves the growth and efficiency of utilization of food in young rats on an 18% casein diet. The deposition of liver fat and the incidence of renal hemorrhagic degeneration in young rats on a low choline diet are increased by supplements of cystine (0.1 to 0.2%) which improve the nutritive value of the diet. Larger supplements of cystine have no effect on the requirement of choline. In the absence of dietary choline, 30% of casein is required to supply sufficient methionine and cystine for the prevention of signs of choline and cystine deficiency. Evidence is presented for the conclusion that methionine which is needed and used as a source of labile methyl is not utilizable as a source of cystine sulphur.