Reduced testosterone during puberty results in a midspermiogenic lesion

The aim of this study was to determine the role of testosterone, as reflected in the testicular interstitial fluid, in the completion of the first wave of spermatogenesis and to further elucidate its role in spermiogenesis. At weekly intervals beginning with 26-day-old rats, body and testis weights were obtained, testicular interstitial fluid testosterone (TIF-T) was assayed, daily sperm production (DSP) was determined, and testicular tissue was structurally analyzed by light and electron microscopy. At 40 days postpartum, half the rats were treated with ethane dimethanesulphonate (EDS) to temporarily reduce Leydig cells. The other half served as controls and were treated with the vehicle. The timing of EDS treatment was just prior to the elongation of spermatids. At Day 47 (1 week after EDS treatment), TIF-T, testis weight, DSP, and number of Leydig cells were significantly reduced. At Day 54 (2 weeks after treatment), TIF-T had returned to the normal adult level, Leydig cell repopulation was apparent, and testis weight was normal. The DSP returned to normal by Day 61 (3 weeks after treatment). At 1 and 2 weeks after treatment, Step 8-9 spermatids were partially or completely detached from Sertoli cells. Results indicate that a temporary reduction of testosterone during the peripubertal period leads to a temporary reduction of the DSP approximately 1 week later. It is suggested that reduced testosterone is associated with a mid-spermiogenic lesion interfering with stable attachment of Step 8-9 spermatids to Sertoli cells during Stage VIII-IX of the spermatogenic cycle.