Efficiency of D-tryptophan as Niacin in rats.
L-tryptophan is a very important precursor of niacin in mammals. Food preparation in which proteins are exposed to an alkali and/or high temperature for a long period generate appreciable amounts of D-amino acids from racemization. The efficiency of D-tryptophan as niacin was thus investigated by using weanling rats. The availability of D-tryptophan was almost the same as that in L-tryptophan as the precursor of niacin and was 1/6 as active as niacin.
Shibata
K
K
Department of Life Style Studies, School of Human Cultures, University of Shiga Prefecture, Japan. kshibata@shc.usp.ac.jp
Swabe
M
M
Fukuwatari
T
T
Sugimoto
E
E
D000818:Animals; D001835:Body Weight / Q000187:drug effects; D004032:Diet; D002149:Energy Intake; D007536:Isomerism; D008297:Male; D009525:Niacin / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D014364:Tryptophan / Q000378:metabolism*
D009525:Niacin; D014364:Tryptophan