Rat liver tryptophan (Trp), kynurenine pathway metabolites, and enzymes deduced from product/substrate ratios were assessed following acute and/or chronic administration of kynurenic acid (KA), 3-hydroxykynurenine (3-HK), 3-hydroxyanthranilic acid (3-HAA), Trp, and the kynureni-nase inhibitors benserazide (BSZ) and carbidopa (CBD). KA activated Trp 2,3-dioxygenase (TDO), possibly by increasing ...

AIMS The tryptophan metabolites 3-hydroxykynurenine (3-HK) and 3-hydroxyanthranilic acid (3-HAA) inhibit the liver mitochondrial low Km aldehyde dehydrogenase and possess alcohol-aversive and immunosuppressant properties. As the disulfiram (DS) metabolite carbon disulphide activates enzymes forming 3-HK and 3-HAA, we investigated if repeated disulfiram treatment increases the hepatic and serum ...

Previous studies from this laboratory have shown that a majority of patients with rheumatoid arthritis excrete abnormally high amounts of 3-hydroxyanthranilic acid and kynurenine (Bett, 1962a, b). A more striking finding was the rise in kynurenine output after tryptophan loading in rheumatoid arthritis. Administration of large doses of pyridoxine over a short period caused a temporary fall in k...

Previous studies from this laboratory have shown that a majority of patients with rheumatoid arthritis excrete abnormally high amounts of 3-hydroxyanthranilic acid and kynurenine (Bett, 1962a, b). A more striking finding was the rise in kynurenine output after tryptophan loading in rheumatoid arthritis. Administration of large doses of pyridoxine over a short period caused a temporary fall in k...

In the mouse hippocampus normal levels of kynurenic acid (KYNA), a neuroactive metabolite synthesized in astrocytes primarily by kynurenine aminotransferase II (KAT II)-catalyzed transamination of L-kynurenine, maintain a degree of tonic inhibition of α7 nicotinic acetylcholine receptors (nAChRs). The present in vitro study was designed to test the hypothesis that α7 nAChR activity decreases wh...

I. Urinary excretion of tryptophan metabolites of the kynurenine pathway before and after a loading dose of 2 g of L-tryptophan (both before and during supplementation with vitamin B6) was studied in normal young male subjects and in elderly male subjects with prostatic diseases. 2. The increase in urinary excretion of tryptophan metabolites in the normal male subjects after a loading dose of 2...

The preferential cleavage of kynurenine peptides bonds was studied through reduction to y-(oaminophenyl)-homoserine derivatives followed by mild acidic as well as mild alkaline hydrolysis. The reduction of keto group of kynurenine to hydroxy one was achieved by controlled potential electrolysis at —1.05 Volts. In order to understand the mechanism of hydrolysis some model com­ pounds related to ...

Central nervous system infection of neonatal and adult rats with Borna disease virus (BDV) results in neuronal destruction and behavioral abnormalities with differential immune-mediated involvement. Neuroactive metabolites generated from the kynurenine pathway of tryptophan degradation have been implicated in several human neurodegenerative disorders. Here, we report that brain expression of ke...

In a previous paper (Bett, 1962), it was reported that a majority of patients with rheumatoid arthritis excreted abnormal amounts of the tryptophan metabolites, 3-hydroxyanthranilic acid and kynurenine. In these experiments the most striking difference between control subjects and patients with rheumatoid arthritis was in the urinary kynurenine output after a loading dose of L-tryptophan. This ...

Both the kynurenine and the endocannabinoid systems are involved in several neurological disorders, such as migraine and there are increasing number of reports demonstrating that there are interactions of two systems. Although their cooperation has not yet been implicated in migraine, there are reports suggesting this possibility. Additionally, the individual role of the endocannabinoid and kyn...