Takahashi Kei, Okuno Alato, Fukuwatari Tsutomu, Shibata Katsumi
Department of Food Science and Nutrition, School of Human Cultures, The University of Shiga Prefecture, Hikone, Shiga, Japan.
Biosci Biotechnol Biochem. 2009 Feb;73(2):274-9. doi: 10.1271/bbb.80372. Epub 2009 Feb 7.
We discovered markedly differing catabolism of nicotinamide among rat strains. We compared the catabolism of nicotinamide and also that of the other tryptophan-nicotinamide and water-soluble vitamins among the four strains, Wistar, Sprague-Dawley (SD), August-Copenhagen Irish (ACI) and Fischer 344. The major urinary catabolite of nicotinamide was N(1)-methyl-4-pyridone-3-carboxamide in Wistar, SD and ACI, and N(1)-methylnicotinamide in Fischer rats. This phenomenon was attributed to the enzyme activity involved in the reaction of N(1)-methylnicotinamide to N(1)-methyl-4-pyridone-3-carboxamide being much lower in Fischer than in the other three strains. With the water-soluble vitamins, this specific phenomenon was only observed in the catabolism of vitamin B(6); the urinary catabolite, 4-pyridoxic acid, was much lower too. It was found for the first time that the activities of oxidase were lower in Fischer than in the other strains. This study showed that Wistar, SD, ACI strains had similar water-soluble vitamin metabolism including nicotinamide catabolism.
我们发现大鼠品系间烟酰胺的分解代谢存在显著差异。我们比较了Wistar、Sprague-Dawley（SD）、奥古斯特-哥本哈根爱尔兰（ACI）和Fischer 344这四个品系中烟酰胺以及其他色氨酸-烟酰胺和水溶性维生素的分解代谢情况。在Wistar、SD和ACI大鼠中，烟酰胺的主要尿中分解代谢产物是N(1)-甲基-4-吡啶酮-3-甲酰胺，而在Fischer大鼠中是N(1)-甲基烟酰胺。这种现象归因于Fischer大鼠中参与N(1)-甲基烟酰胺转化为N(1)-甲基-4-吡啶酮-3-甲酰胺反应的酶活性远低于其他三个品系。对于水溶性维生素，这种特殊现象仅在维生素B(6)的分解代谢中观察到；尿中分解代谢产物4-吡哆酸也低得多。首次发现Fischer大鼠中氧化酶的活性低于其他品系。这项研究表明，Wistar、SD、ACI品系具有相似的水溶性维生素代谢，包括烟酰胺分解代谢。
