Gonadal Steroid Sulfates and Sulfatase. III. Correlation of Human Testicular Sulfatase, 3β-Hydroxysteroid Dehydrogenase-Isomerase, Histologic Structure and Serum Testosterone1

Abstract

To evaluate the role of steroid sulfates as precursors of testosterone in the human testis, the rate of cleavage of pregnenolone sulfate, dehydroepiandrosterone sulfate and androstenediol-3-sulfate was determined in the microsomal fraction of testes from 11 patients (27–80 yrs), three of whom had been on estrogen therapy prior to orchiectomy. The conversion of free Δ⁵-3β-hydroxysteroids to their Δ⁴-3-ketosteroid analogs, an obligatory reaction in testosterone biosynthesis, was determined separately in the same fractions with pregnenolone, dehydroepiandrosterone and androstenediol as substrates. Sections of each testis were examined histologically and Leydig cells quantitated. Serum testosterone levels were determined in 6 of the patients. Steroid sulfatase and 3β-hydroxysteroid dehydrogenase-isomerase activities were significantly reduced in the patients who had received estrogen therapy (Group I) when compared to those in non-treated patients (Group II). Mean “Leydig Cell Activity Index” (functioning Leydig cells/total interstitial cells × 100) was 7.3±3.3 (sd) for Group I and 47.9±9 (sd) for Group II. There was no correlation of enzyme activities with degree of spermatogenesis or prevalence of Sertoli cells. Excellent correlation was found between enzyme activities and serum testosterone levels. The data are interpreted as implicating steroid sulfates as precursors of testosterone in the human testis.