Shibata K, Kakehi H, Matsuo H
Department of Food Science and Nutrition, Teikoku Women's University, Osaka, Japan.
J Nutr Sci Vitaminol (Tokyo). 1990 Apr;36(2):87-98. doi: 10.3177/jnsv.36.87.
Urinary excretion of nicotinamide and its metabolites in mouse, guinea pig, and hamster with a pharmacological amount of nicotinamide or N1-methylnicotinamide (MNA) was investigated to compare them with those of rat. In mouse, nicotinamide N-oxide was the most abundant metabolite, accounting for 35% of urinary excretion of nicotinamide and its metabolites, and followed by N1-methyl-2-pyridone-5-carboxamide (2-Pyr), 20%; nicotinamide, 18; MNA, 16%; and N1-methyl-4-pyridone-3-carboxamide (4-Pyr), 11%. In guinea pig, 2-Pyr was the most abundant metabolite, accounting for 80% of urinary excretion, and was followed by MNA, 11%; nicotinamide, 3%; 4-Pyr, 3%; and nicotinamide N-oxide, 3%. In hamster, nicotinamide was the most abundant metabolite, accounting for 44%, and followed by 2-Pyr, 21%; nicotinamide N-oxide, 15%; MNA, 10%; and 4-Pyr, 10%. Urinary excretion of nicotinic acid and nicotinuric acid was not detected in mouse, guinea pig, and hamster. When a pharmacological amount of nicotinamide was intraperitoneally injected into mouse, the excretion of nicotinamide N-oxide increased to 79.7% of the nicotinamide metabolites, while those of MNA (4.9%), 2-Pyr (11.2%), and 4-Pyr (6.3%) decreased. Nicotinic acid and nicotinuric acid were again not detected. When a pharmacological amount of nicotinamide was intraperitoneally injected into guinea pig and hamster, the deamidated metabolites nicotinic acid and nicotinuric acid occupied significant percentages of the nicotinamide metabolites: 50.4% and 26.3%, respectively, in guinea pig; and 7.7% and 79.5%, respectively, in hamster. The ratio of 2-Pyr to 4-Pyr excretion did not change when nicotinamide or MNA was located into mouse, guinea pig, and hamster. From these results, the catabolism of nicotinamide in rodent is discussed.
研究了给予药理剂量的烟酰胺或N1-甲基烟酰胺（MNA）后，小鼠、豚鼠和仓鼠中烟酰胺及其代谢产物的尿排泄情况，并与大鼠进行比较。在小鼠中，烟酰胺N-氧化物是最主要的代谢产物，占烟酰胺及其代谢产物尿排泄量的35%，其次是N1-甲基-2-吡啶酮-5-甲酰胺（2-Pyr），占20%；烟酰胺占18%；MNA占16%；N1-甲基-4-吡啶酮-3-甲酰胺（4-Pyr）占11%。在豚鼠中，2-Pyr是最主要的代谢产物，占尿排泄量的80%，其次是MNA，占11%；烟酰胺占3%；4-Pyr占3%；烟酰胺N-氧化物占3%。在仓鼠中，烟酰胺是最主要的代谢产物，占44%，其次是2-Pyr，占21%；烟酰胺N-氧化物占15%；MNA占10%；4-Pyr占10%。在小鼠、豚鼠和仓鼠中均未检测到烟酸和烟尿酸的尿排泄。当给小鼠腹腔注射药理剂量的烟酰胺时，烟酰胺N-氧化物的排泄量增加到烟酰胺代谢产物的79.7%，而MNA（4.9%）、2-Pyr（11.2%）和4-Pyr（6.3%）的排泄量减少。再次未检测到烟酸和烟尿酸。当给豚鼠和仓鼠腹腔注射药理剂量的烟酰胺时，脱酰胺代谢产物烟酸和烟尿酸在烟酰胺代谢产物中占显著比例：在豚鼠中分别为50.4%和26.3%；在仓鼠中分别为7.7%和79.5%。当给小鼠、豚鼠和仓鼠注射烟酰胺或MNA时，2-Pyr与4-Pyr的排泄比例没有变化。根据这些结果，讨论了啮齿动物中烟酰胺的分解代谢。
