Action inhibitrice de la prolactine sur les ultrastructures des vesicules seminales de Discoglossus pictus otth (amphibien anoure)

Abstract

Prolactin (ovine, NIH-P-S4) induces marked ultrastructural changes in different cell types of the seminal vesicles of the Anuran Discoglossus pictus. Overall, prolactin antagonises the action of androgen. Following daily injection of prolactin for 3 days in intact animals, seminal vesicle secretory cells undergo regression. The Golgi apparatus develops lysosomal activity involved in the degradation of secretion granules. Numerous autophagic vacuoles appear and surround cell organelles. These autolytic processes provoke cell destruction. In castrated animals, the same autolytic process prominently occurs. In both animals, intact and castrate, prolactin induces a loss of cilia. No mitosis occurs in the undifferentiated basal cells. Our results demonstrate that prolactin produces ultrastructural alterations similar to those observed during the mating period. Prolactin cells in the pars distalis become quickly degranulated during the mating period. Prolactin which directly inhibits seminal vesicle secretory activity and development would appear to be implicated in the endocrine control of the seminal vesicles from Discoglossus pictus.