Comparative Effect of Tryptophan, Niacin, and Nicotinamide in Forming Liver Pyridine Nucleotides.

Abstract

Changes in the level of liver pyridine nucleotides (PN) of rats were studied at various times following admn. by stomach tube of equimolar amts. of tryptophan, niacin, or niacinamide. Tryptophan was observed to be equally as effective as a PN precursor as equimolar amts. of niacin, whereas niacinamide produced significantly higher levels of liver PN than either tryptophan or niacin. When incorporated directly into the ration, however, niacin and tryptophan were again equivalent as PN precursors whereas, under these conditions, . niacinamide was a slightly less efficient PN precursor than niacin or tryptophan.