期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：1997
卷号：43
期号：4
页码：479-483
DOI：10.3177/jnsv.43.479
出版社：Center for Academic Publications Japan
摘要：The effect of a vitamin B1-free diet on the conversion ratio of tryptophan to niacin in rats was investigated using the current methods for determination of the intermediate metabolites. Rats were fed with diets with or without B1 for 33 days. The body weight gain and food intake in the B1-free group were almost the same as the control group for 10 days, but, they steeply dropped after that time and the conversion ratio of tryptophan to niacin began to increase. The ratio reached 7-fold that of the control group on the last day of the experiment. This finding seriously differed from the previous reports, which described that B 1 was needed in the first part of tryptophan conversion to niacin and that the conversion ratio of tryptophan to niacin decreased in B1-deficient rats. Furthermore, the activity of tryptophan oxygenase, in which it was reported that B 1 is required for the tryptophan catalytic reaction, did not decrease but increased even when the B1-free diet was fed. These results suggest that there is a very small possibility of the direct involvement of B 1 in the conversion of tryptophan to niacin.
关键词：vitamin B1;tryptophan metabolism;nicotinamide;conver-sion ratio of tryptophan to niacin
