Donner I, Kröger H
Hoppe Seylers Z Physiol Chem. 1976 Jun;357(6):811-7.
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.
多种酶可由甾体激素诱导产生。本文对色氨酸2,3-双加氧酶的反应进行了进一步分析。特别是我们展示了底物和低剂量可的松以何种方式引起诱导作用。1）对于用2.5毫克可的松/千克诱导肾上腺切除大鼠体内的色氨酸2,3-双加氧酶，底物的存在也是必需的。在这些条件下，当存在12.5毫克L-色氨酸/千克时，即可检测到该酶的诱导作用。2）在预先用可的松处理过的动物中，酶活性在注射L-色氨酸后30分钟达到最大值。对于预先用2.5毫克可的松/千克处理过的动物，仅在注射L-色氨酸后30分钟内，放线菌酮会抑制酶活性的增强。3）对用低剂量可的松处理过的动物进行的抗体实验表明，L-色氨酸分别主要通过酶降解或与辅酶血红素饱和发挥作用。
