Studies with tryptophan metabolites in vitro. Kynurenine metabolism in liver homogenates of normal and Schistosoma mansoni-infested mice.
The conversion of kynurenine into kynurenic acid and anthranilic acid in both normal and Schistosoma mansoni-infested mouse liver was investigated. It was found that in the S. mansoni-infested mouse liver there is probably a deficiency of pyridoxal phosphate that resulted in an inhibition of kynurenine transaminase and a low production of kynurenic acid. Deoxypyridoxine and its phosphorylated derivative inhibited kynurenine transaminase in the normal liver in a pattern qualitatively similar to that observed with infested liver. The lowered concentration of pyridoxal phosphate in the infested liver is discussed in view of the possibility of two combined mechanisms: (a) an antimetabolite being secreted by the infesting worms or present in its eggs that partially inhibited the phosphorylation of pyridoxal, and (b) concentration of pyridoxal phosphate by the worms, resulting in a lowered concentration of the cofactor in the host tissue.
D000818:Animals; D007700:Kinetics; D007737:Kynurenine / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D051379:Mice; D010477:Perfusion; D011732:Pyridoxal Phosphate / Q000378:metabolism; D011736:Pyridoxine / Q000494:pharmacology; D012552:Schistosomiasis / Q000378:metabolism*; D014364:Tryptophan / Q000378:metabolism*; D062367:ortho-Aminobenzoates / Q000378:metabolism
D062367:ortho-Aminobenzoates; D007737:Kynurenine; D011732:Pyridoxal Phosphate; D014364:Tryptophan; D011736:Pyridoxine