Spermatogenesis and blood-testis barrier in rats after long-term Vitamin A deprivation.

It has been established that experimental avitaminosis A in rats results in a 'Sertoli cell-only situation' after about 10 weeks, and that replacing the vitamin immediately reinitiates spermatogenesis. The present study deals with testicular recovery after prolonged deprivation (up to 19 weeks). The Sertoli cell-only situation reached under this condition was thought to be refractory to Vitamin A replacement. However, spermatogenesis did reinitiate about 11 weeks after vitamin restoration, although in an atypical manner. The blood-testis barrier, normally assembled when spermatocytes reaches the zygotene stage, remained under this condition permeable to the lanthanum intercellular tracer. Concomitantly, primary spermatocytes normally found in the adluminal compartment isolated by the barrier (zygotene onward) became massively apoptotic. All the tubules containing early spermatocytes (preleptotene or leptotene cells), normally found in the basal compartment, exhibited normal features with no signs of degeneration. Based on these results, a possible relationship between blood-testis barrier assembly and spermatocyte differentiation is proposed.