The Sulfur Balance of Rats Fed Excess Dl- Methionine plus Glycine or Dl-alanine* by Jay

It has been demonstrated that when mature, male, Sherman strain rats are fed 4.8 per cent DL-methionine while on a 12 per cent casein diet the animals soon attain nitrogen equilibrium or a small positive nitrogen balance (1, 2). The rats lose weight, however, even in positive balance, this loss resulting from a decrease in the fat stores of the body. At the end of 20 days the fat deposits are markedly reduced. A hypertrophy of the kidney of approximately 30 per cent over control values is also noted. The addition of 4.8 per cent glycine to this diet partly counteracts the loss in weight and kidney hypertrophy. It has been suggested (2) that t,he glycine may serve as an additional source of the serine (3, 4) needed for methionine catabolism. If this is so, the effect of the glycine should be fairly specific. To test this point extra m-alanine was fed, and to study further the relationships between the metabolism of fat and methionine and the effects of added glycine, sulfur balances and urinary distribution of sulfur were determined in four groups of rats.