Biomaterial Database

Conversion ratio of tryptophan to niacin in rats fed a vitamin B1-free diet. 1997

K Shibata, and T Kondo, and M Yonezima

Department of Human Health Science, Faculty of Human Sciences, Osaka International University for Women, Japan.

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 B1 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 B1 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 B1 in the conversion of tryptophan to niacin.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009525	Niacin	A water-soluble vitamin of the B complex occurring in various animal and plant tissues. It is required by the body for the formation of coenzymes NAD and NADP. It has PELLAGRA-curative, vasodilating, and antilipemic properties.	Nicotinic Acid,3-Pyridinecarboxylic Acid,Enduracin,Induracin,Lithium Nicotinate,Niacin Aluminum Salt,Niacin Ammonium Salt,Niacin Calcium Salt,Niacin Cobalt (2+) Salt,Niacin Copper (2+) Salt,Niacin Hydrochloride,Niacin Iron (2+) Salt,Niacin Lithium Salt,Niacin Lithium Salt, Hemihydrate,Niacin Magnesium Salt,Niacin Manganese (2+) Salt,Niacin Potassium Salt,Niacin Sodium Salt,Niacin Tartrate,Niacin Tosylate,Niacin Zinc Salt,Nicamin,Nico-400,Nicobid,Nicocap,Nicolar,Nicotinate,Wampocap,3 Pyridinecarboxylic Acid,Aluminum Salt, Niacin,Hydrochloride, Niacin,Nico 400,Nico400,Nicotinate, Lithium,Potassium Salt, Niacin,Sodium Salt, Niacin,Tartrate, Niacin,Tosylate, Niacin
D004032	Diet	Regular course of eating and drinking adopted by a person or animal.	Diets
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D013831	Thiamine	3-((4-Amino-2-methyl-5-pyrimidinyl)methyl)-5-(2- hydroxyethyl)-4-methylthiazolium chloride.	Aneurin,Vitamin B 1,Thiamin,Thiamine Mononitrate,Vitamin B1,Mononitrate, Thiamine
D014364	Tryptophan	An essential amino acid that is necessary for normal growth in infants and for NITROGEN balance in adults. It is a precursor of INDOLE ALKALOIDS in plants. It is a precursor of SEROTONIN (hence its use as an antidepressant and sleep aid). It can be a precursor to NIACIN, albeit inefficiently, in mammals.	Ardeydorm,Ardeytropin,L-Tryptophan,L-Tryptophan-ratiopharm,Levotryptophan,Lyphan,Naturruhe,Optimax,PMS-Tryptophan,Trofan,Tryptacin,Tryptan,Tryptophan Metabolism Alterations,ratio-Tryptophan,L Tryptophan,L Tryptophan ratiopharm,PMS Tryptophan,ratio Tryptophan
D014366	Tryptophan Oxygenase	A dioxygenase with specificity for the oxidation of the indoleamine ring of TRYPTOPHAN. It is a LIVER-specific enzyme that is the first and rate limiting enzyme in the kynurenine pathway of TRYPTOPHAN catabolism.	Tryptophan Pyrrolase,TDO Dioxygenase,Tryptophan 2,3-Dioxygenase,2,3-Dioxygenase, Tryptophan,Dioxygenase, TDO,Oxygenase, Tryptophan,Pyrrolase, Tryptophan,Tryptophan 2,3 Dioxygenase
D017208	Rats, Wistar	A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.	Wistar Rat,Rat, Wistar,Wistar Rats
D051381	Rats	The common name for the genus Rattus.	Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus