Interaction between Methionine, Fat and Choline in the Young Rat

Abstract

The effect of different levels of choline and methionine and of choline and fat on growth and lipotropic activity in weanling rats was measured, using a factorial design. When 0, 44 and 88 mg choline and 288, 374 and 547 mg methionine were incorporated per 100 g of diets containing adequate amounts of other essential amino acids and 5% fat, dietary choline significantly altered (P < 0.01) only the concentrations of choline and lipid in the liver. In contrast, methionine influenced food intake, growth and nitrogen deposition but did not exert a significant lipotropic effect, although it stimulated biosynthesis of choline. When 0, 22, 44, 66 and 88 mg choline were fed in conjunction with 415 mg methionine and 5, 10 or 15% fat, dietary choline decreased (P < 0.01) the concentration of hepatic lipid and moisture but did not significantly alter choline. Increasing dietary fat from 5 to 15% decreased (P < 0.01) food intake, weight gain and concentration of moisture but not of choline in the liver; and 15% fat caused a greater accumulation of lipid in the liver in the absence of choline than did 5 or 10% fat. There was significant interaction between dietary choline and methionine only in respect to weight gain and liver weight (P < 0.05), and between choline and fat in respect to lipid and moisture in fresh liver (P < 0.01).