Effect of bacterial endotoxin and inhibitors on tryptophan oxygenase induction in mouse liver slices.
Tryptophan oxygenase activity in mouse liver slices maintained in cluture medium, in Krebs-Ringer bicarbonate solution, or in homologous whole blood declined within 3 hr to about one-half the original level. Actinomycin D and puromycin accelerated the rate of decline, but endotoxin did not. Direct addition of tryptophan to the medium resulted in a higher than normal tryptophan oxygenase activity within 1 hr, and this was maintained well above that of control liver slices up to 6 hr. Triamcinolone, at a dose that doubles tryptophan oxygenase activity in vivo, had no effect on the enzyme in liver slices. Actinomycin and endotoxin did not alter the substrate induction of tryptophan oxygenase; however, puromycin did, but to a limited extent. Liver slices prepared from mice 4 hr after an injection of cortisone had a greater tryptophan oxygenase activity than those of controls. Either endotoxin or actinomycin D resulted in a more rapid decline of the enzyme when added to the slices than was observed in the controls.
D000818:Animals; D003348:Cortisone / Q000494:pharmacology; D003470:Culture Media / Q000494:pharmacology; D046508:Culture Techniques; D003609:Dactinomycin / Q000494:pharmacology*; D004731:Endotoxins / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D008099:Liver / Q000187:drug effects* / Q000201:enzymology; D051379:Mice; D011691:Puromycin / Q000494:pharmacology*; D014221:Triamcinolone / Q000494:pharmacology; D014364:Tryptophan / Q000494:pharmacology; D014366:Tryptophan Oxygenase / Q000378:metabolism*
D003470:Culture Media; D004731:Endotoxins; D003609:Dactinomycin; D014221:Triamcinolone; D011691:Puromycin; D014364:Tryptophan; D014366:Tryptophan Oxygenase; D003348:Cortisone