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：1989
卷号：35
期号：5
页码：383-391
DOI：10.3177/jnsv.35.383
出版社：Center for Academic Publications Japan
摘要：The effects of large amounts of tryptophan, Pyrazinamide, or nicotinic acid in diets on the contents of total NAD (NAD+NADH) and NADP (NADP + NADPH) of various organs were investigated in mice with or without γ-irradiation. Female C3H/HeN mice were fed one of the following 4 kinds of experimental diets for one week: l) control diet (20% casein diet containing 3 mg niacin per 100 g diet); 2) diet supplemented by 0.5% L-tryptophan (T-diet); 3) diet supplemented by 0.5% L-tryptophan (T-diet); 3) diet supplemented by 0.5% pyrazinamide and 0.5% L-tryptophan (PT-diet); 4) diet supplemented by 0.1% nicotinic acid (NA-diet). Half of the mice in each group were subsequently irradiated with 8 Gy of y-ray (60Co) after 4 h of fasting. Then, the contents of total NAD and NADP in thymus, spleen, kidney, liver, and blood were determined in all animals. The results indicated that NAD content of spleen was higher in PT-group (21.5%) and NA-group (23.2%) than in that of control group. In thymus, however, NAD content of only the PT-group was significantly greater (13.1%) than control. NAD level of kidney was also significatly higher (32.6%) in PT-group. By γ-irradiation, NAD contents of thymus and spleen of all groups tended to be decreased, but those of kidney and liver were not always reduced. In the latter two organs, significant NAD reduction was shown only in kidney of PT-group and in liver of PT and NA-groups. Even after irradiation, NAD levels of spleen and thymus in PT and NA-groups tended to be kept higher than those in irradiated control group. On the other hand, NADP contents of all kinds of organs examined were not significantly affected by those dietary supplements. By the γ-irradiation, however, NADP levels of spleen and thymus were decreased remarkably in all dietary groups. NAD and NADP contents of blood were not significantly affected by those dietary supplements, and their levels were not altered by γ-irradiation except that NAD levels of T and NA-groups were slightly increased. These results indicate that ingestion of pyrazinamide-tryptophan or nicotinic acid influences the contents of pyridine nucleotides in some tissues and that such alteration affects the radiation-induced NAD(P) reduction in those tissues, a reduction which is possibly caused mainly by poly(ADP-ribose) synthesis reaction.
