Concentration of Androgens in Whole Testis, Seminiferous Tubules and Interstitial Tissue of Rats at Different Stages of Development¹

Abstract

Endogenous concentrations of testosterone (T), 5µ-androstan-3µ,17β-diol (DIOL) and dihydrotestosterone (DHT) were determined in whole testis, seminiferous tubules and interstitial tissue of rats from 10 to 90 days of age. Contents in whole testis were very close to the sum of the contents in seminiferous tubules and interstitial tissue. In seminiferous tubules the concentration of T increased from 39 ng/100 mg proteins at 14 days to 94 at 20 days, and then dropped to 13 at 26 days. There was a gradual increase thereafter to reach again a value of 94 at sexual maturation. The concentration of DIOL also increased from 21 to 89 in 20-day-old rats, but it remained high in 26-day-old animals, only to drop thereafter and remain low through sexual maturation. The concentration of DHT did not show a definite peak in young rats but increased markedly between 60 and 90 days of life. The concentrations of T in interstitial tissue were much higher than in seminiferous tubules at all ages; values were between 800 and 900 in young rats and increased to approximately 4000 ng⁄100 mg proteins in adult animals. DIOL and DHT could not be detected in this tissue. It is speculated that T and DIOL might be the active androgens in the seminiferous tubules at the time of meiosis while T and DHT might be preponderant in rats with mature spermatogenesis. (Endocrinology95: 455, 1974)