Effect of Lipid Peroxidation Products on the Catabolic Fate of Nicotinamide in Rats

high-performance liquid chromatographic measurements of nicotinamide3' and its major catabolic metabolites such as MNA,4) 2-Py,5) and A^-methyM-pyridone-S-carboxamide (4-Py),6) and have been investigating the effects of nutrients on the metabolic fate of nicotinamide in rats. However, our results did not indicate any evident relationship between the urinary excretion of (2-Py+4Py)/MNAand niacin status. Under speciffed conditions, its excretion ratio reflected an adequacy of amino acid nutrition,7~12) and even when the amino acid nutrition was adequate, an excess administration of tryptophan,13)