Identification and cellular localisation of voltage-operated calcium channels in immature rat testis

Sertoli cells regulate the spermatogenic process mainly through the secreti on of a complex fluid into the lumen of the seminiferous tubules behind the blood-testis barrier, containing many of the essential proteins necessary for maintenance and maturation of male germ cells. Thus, the study of Serto li cell secretory processes is strictly correlated with the understanding o f the regulatory mechanisms of spermatogenesis. In this work the authors ha ve explored the voltage-sensitive calcium channel variety in the immature r at testis. their localisation and distribution within the seminiferous epit helium and peritubular and interstitial tissues as well as the possible rol e in the control of Sertoli cell secretion. The results reported in this pa per, obtained by in situ hybridisation. immunohistology of rat testicular s ections and Western blot analysis of Sertoli cell plasma membranes, show th at mammalian Sertoli cells express mRNA encoding for several voltage-operat ed calcium channel subunits and express such proteins on their surface. Exp eriments performed on Sertoli cell monolayers cultured in the presence of s pecific toxins indicate that both N and P,Q-type Ca2+ channels are involved in the regulation of protein secretion. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.