Biosynthesis of steroids from cholesterol- 14C by human adrenal carcinoma tissue

Abstract

Slices prepared from human adrenal carcinoma tissue obtained froa a 51 year old female with virilism were incubated with cholesterol-4- 14C (l) in the presence and absence of ACTH or cyclic AMP. The tissue homogenates were analyzed for steroids by the reverse isotope dilution method. Purification and identification of the radio-active metabolites were achieved by column, paper and thin-layer chromatography, derivative formation and crystallization to constant specific activity. Cholesterol- 14C was converted to pregnenolone- 14C (0.75%), progesterone- 14C (0.17%) and dehydroepiandrosterone- 14C(0.15%). No evidence was found for the formation of labeled 17-hydroxyprogesterone, androstenedione, testosterone, and estrogens. Addition of ACTH to the incubations resulted in a two-fold inoreas of radioactive pregnenolone- 14C and or dehydroepiandrosterone- 14C. A two-fold increase of progesterone- 14C synthesis was found in cyclic AMP-stimulated incubations.