The effect of phenytoin on the corticoidogenesis in the mitochondria and the endoplasmic reticulum of bovine adrenal cortex.

In the mitochondria and endoplasmic reticulum of bovine adrenal cortex, the influence of phenytoin on corticoidogenesis was studied using 0.1 microCi 4-14C-cholesterol, 0.01 microCi 4-14C-17 alpha-hydroxyprogesterone, deoxycorticosterone and NADPH-generating system. The cholesterol side-chain cleaving activity in the mitochondria was facilitated by 0.1 microM phenytoin, but was inhibited by higher concentrations. Steroid 11 beta-hydroxylase activity was inhibited by phenytoin. The steroid 21-hydroxylase activity in the endoplasmic reticulum, on the contrary, was mildly stimulated by 1 and 10 microM phenytoin. Phenytoin formed a modified type I spectrum in the adrenocortical mitochondria-malate complex.