[Effect of substrate and small doses of cortisone on the induction of Tryptophan 2,3-dioxygenase (author's transl)].
A number of enzymes are induced by steroid hormones. In this paper the reaction of tryptophan 2,3-dioxygenase is further analyzed. In particular we show in which way the substrate and low doses of cortisone cause an induction. 1) For the induction of tryptophan 2,3-dioxygenase in adrenalectomized rats by 2.5 mg cortisone/kg, the presence of the substrate is necessary as well. Under these conditions an induction of the enzyme can already be registered in the presence of 12.5 mg L-tryptophan/kg. 2) In animals treated before with cortisone, the enzyme maximum appears 30 min after L-tryptophan injection, The enhancement of enzyme activity in animals which are treated with 2.5 mg cortisone/kg before is blocked by actidione only until 30 min after L-tryptophan injection. 3) Experiments with antibodies in animals treated with a low dosis of cortisone show that L-tryptophan acts mainly via enzyme degradation or the saturation with the coenzyme hematin, respectively.
D000315:Adrenalectomy; D000818:Animals; D000906:Antibodies / Q000032:analysis; D005558:Arylformamidase / Q000302:isolation & purification; D003348:Cortisone / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D007930:Leucine / Q000378:metabolism; D051381:Rats; D014364:Tryptophan / Q000494:pharmacology*; D014366:Tryptophan Oxygenase / Q000096:biosynthesis* / Q000276:immunology
D000906:Antibodies; D014364:Tryptophan; D014366:Tryptophan Oxygenase; D005558:Arylformamidase; D007930:Leucine; D003348:Cortisone
Wirkung von Substrat und kleinen Dosen Cortison auf die Induktion der Tryptophan-2,3-Dioxygenase