Leucine and tryptophan metabolism in rats.
The rate of tryptophan metabolism in isolated liver cells from animals fed on a high-leucine diet was greater than for cells from control animals. Leucine inhibited tryptophan metabolism and tryptophan uptake in isolated liver cells, probably by competing for membrane transport. Leucine had no effect on tryptophan 2,3-dioxygenase in vitro. 4-Methyl-2-oxovalerate increased tryptophan oxidation in incubations containing albumin, by displacing bound tryptophan and increasing the availability of the amino acid to the cell. The results suggest that, under extreme conditions, when the availability of tryptophan is low, leucine may be pellagragenic.
D000818:Animals; D066298:In Vitro Techniques; D007930:Leucine / Q000378:metabolism* / Q000494:pharmacology; D008099:Liver / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D014364:Tryptophan / Q000378:metabolism*; D014366:Tryptophan Oxygenase / Q000378:metabolism
D014364:Tryptophan; D014366:Tryptophan Oxygenase; D007930:Leucine