Steroid 21-hydroxylase and 17 alpha-hydroxylase in microsomal fraction of functioning adrenocortical tumors.

In order to survey the enzymic activities of steroidogenesis in functioning adrenocortical tumors, we investigated the activities of steroid 21-hydroxylase and 17 alpha-hydroxylase in microsomal fractions of 12 surgically resected adrenocortical tumors associated with Cushing's syndrome (5 adenomas and one carcinoma), primary aldosteronism (5 adenomas) and adrenogenital syndrome (AGS) (one carcinoma), and one adrenocortical hyperplasia resulting from Cushing's disease. Seven adrenal cortices from the patients with mammary carcinoma, renal cell carcinoma or pheochromocytoma were used for normal control. In normal controls 21-hydroxylase activities with progesterone as a substrate were 1.61 +/- 0.25 nmole/min/mg protein and those with 17 alpha-hydroxyprogesterone were 5.22 +/- 1.06 nmole/min/mg protein. The activity of 21-hydroxylase was higher in four cases of 5 aldosteronomas than in normal controls. Those activities in Cushing's adenomas were in the range of normal controls in this study. 17 alpha-hydroxylase activities were much variable from case to case even though in normal controls (4.50 +/- 2.40 nmole/min/mg protein), and in most cases of adenomas 17 alpha-hydroxylase activities were in the range of normal controls. Activities of both hydroxylase in carcinomas were lower than in normal controls. The present paper showed the abnormal steroidogenic enzyme activities in aldosteronomas and adrenocortical carcinomas.