Specific features of steroidogenesis in hormally active and hormonally inactive tumors of the adrenal cortex

Abstract

The papers examines the specific features ofsteroidogenesis in the adrenal cortex ofpatients with different types of tumors and analyzes the ratio of ∆4- to ∆5-pathways of corticosteroid biosynthesis, which is a governing factor in the development of adrenal cortical hyperfunction. The levels of all major corticosteroids (cortisol, aldosterone, androgens of the adrenals) and their precursors were studied in the peripheral blood of patients with corticosteroma, aldosteroma, androsteroma, and hormonally inactive tumors (in the morning and in the evening). Based on the calculation of the mean daily concentration of steroids and the ratio of product/substrate of an enzymatic reaction in the biosynthesis of corticosteroids, the authors determined the activity of some enzymes and analyzed the changes found in this activity as compared with the normal values.
 The findings indicate that in corticosteroma, the higher activity of 11β-hydroxylase and the lower activity of 17,20-desmolase leads to a biosynthesis shift to ∆4-pathway; in virilizing tumor, the enhanced activity of Зβ-olsteroid dehydrogenase results in the same shift; in aldosteroma, the ratio of biosynthesis pathways does not differ from the normal values. The significant scatter in the individual values when the blood concentrations were determined in patients with hormonally inactive tumors fails to make an unambiguous conclusion about the activity of steroidogenic enzymes and about the direction of biosynthesis in these patients.