CONTRACTILE RESPONSE OF PERITUBULAR MYOID CELLS TO PROSTAGLANDIN-F2-ALPHA

Prostaglandin (PG) F-2 alpha, a well known agonist of smooth muscle, i s produced in the male gonad. We have investigated whether PG F-2 alph a, stimulates seminiferous tubule contractility through direct action on peritubular myoid cells. Myoid cells from prepubertal rats were hig hly purified through Percoll density gradient and cultured in vitro. S timulation with PG F-2 alpha was observed to induce: (i) rapid and dos e-dependent production of inositol phosphates; (ii) mobilization of Ca 2+ from intracellular stores and (iii) cell contraction. Moreover, at a concentration of 10 mu M the agonist was found to induce immediate c ontractile response of peritubular tissue in freshly explanted tubular fragments from both young and adult rats; the explants were examined in whole-mount preparations and the peritubular myoid cell layer was i dentified by selective staining for alkaline phosphatase activity. Our observations demonstrate that myoid cells are a direct target for PG F-2 alpha and suggest a role of the eicosanoid in the intragonadal con trol of seminiferous tubule contractility. (C) 1998 Elsevier Science I reland Ltd. All rights reserved.