To assess the role of the kynurenine pathway in the pathology of Alzheimer's disease (AD), the expression and localization of key components of the kynurenine pathway including the key regulatory enzyme tryptophan 2,3 dioxygenase (TDO), and the metabolites tryptophan, kynurenine, kynurenic acid, quinolinic acid and picolinic acid were assessed in different brain regions of triple transgenic AD ...

The investigations of Starr (1) demonstrated that Xunthomonas pruni requires an exogenous source of nicotinic acid when grown on a medium containing vitamin-free, acid-hydrolyzed casein, methionine, or glutamic acid to provide an organic form of nitrogen. Preliminary work in this laboratory showed that tryptophan could replace nicotinic acid for growth in a similar medium. This was the first kn...

Quinolinic acid phosphoribosyltransf erase was purified WI-fold from the endosperm of etiolated seedlings of Ricinus communis L. Sodium dodecyl sulfate disc gel electrophoresis indicated that the enzyme was homogeneous but on analytical disc gel electrophoresis at pH 7.0 and 8.3 the isolated native protein exhibited three closely migrating bands. The three proteins were of the same molecular we...

A system is described for chronic intracranial drug administration in the rat using a modified in vivo microdialysis probe coupled to an Alzet model 2002 osmotic minipump. The results presented demonstrate that this system can be used for the chronic administration of quinolinic acid with minimal non-specific damage. Each pump delivered approximately 225 microliters of solution over a period of...

UNLABELLED The purpose of this study was to determine the functional recovery of the transplanted induced pluripotent stem cells in a rat model of Huntington's disease with use of 18F-FDG microPET/CT imaging. METHODS In a quinolinic acid-induced rat model of striatal degeneration, induced pluripotent stem cells were transplanted into the ipsilateral lateral ventricle ten days after the quinol...

BACKGROUND Tryptophan is an essential amino acid for the synthesis of proteins and important metabolites such as serotonin, melatonin, tryptamine and niacin. After protein synthesis, more than 90 % of tryptophan catabolism occurs along the kynurenine pathway. The inflammation-inducible enzyme indoleamine 2,3 dioxygenase (IDO) is responsible for the first rate-limiting step in the kynurenine pat...

Biosynthesis of niacin from 3-hydroxyanthranilic acid (3-OHAA) in normal and streptozotocin diabetic rats was studied in vivo and in vitro. Streptozotocin (SZ) diabetic rats were found to excrete lesser quantities of 3-OHAA, quinolinic acid, niacin and N1-methylnicotinamide (nmn) in their urines following 3-OHAA administration than corresponding normal rats. In vitro studies indicated that SZ d...

The aim of this article is to report the organ-specific correlation with tryptophan (Trp) metabolism obtained by analyses of tryptophan 2,3-dioxygenase knockout (TDO-KO) and quinolinic acid phosphoribosyltransferase knockout (QPRT-KO) mice models. We found that TDO-KO mice could biosynthesize the necessary amount of nicotinamide (Nam) from Trp, resulting in the production of key intermediate, 3...