PROSTAGLANDINS AND REPRODUCTION IN MALE LIZARD, PODARCIS-SICULA-SICULA

The possible role of prostaglandins in the reproductive processes of the male lizard, Podarcis sicula sicula, was investigated. The plasma levels of prostaglandin F-2 alpha (PGF(2 alpha)), prostaglandin E(2) (PGE(2)), progesterone, androgens, and 17 beta-estradiol, and the in vitro basal release of these hormones by testis, epididymis and interrental, at different phases of the annual sexual cycle, were studied. In addition, the in vivo and in vitro effects of PGF(2 alpha) and PGE(2) on steroid production were evaluated. In in vivo experiments, PGF(2 alpha) and 17 beta-estradiol plasma levels were highest during the refractory phase; PGE(2) values were lowest and androgens highest in fighting phase. PGF(2 alpha) injection increased 17 beta-estradiol in refractory phase; PGE(2) increased androgens in fighting phase and 17 beta-estradiol in refractory phase. In in vitro experiments, testis released the highest levels of PGF(2 alpha) and 17 beta-estradiol in refractory phase, and of PGE(2) and androgens in fighting phase. Interrenal released the highest levels of PGF(2 alpha), PGE(2), and 17 beta-estradiol in refractory phase, and of androgens in fighting phase. Epididymis released the highest values of PGF(2 alpha) and PGE(2) in mating phase. PGF(2 alpha) treatment increased 17 beta-estradiol release by testis and interrenals in refractory phase. PGE(2) treatment increased androgen release by testis in fighting phase and 17 beta-estradiol release by interrenal in refractory phase. The present data indicate that in male lizards, P. s. sicula, testicular androgen synthesis during the fighting phase is under the control of PGE(2), while 17 beta-estradiol synthesis during refractory phase is regulated in the testis by PGF(2 alpha) and in interrenal by PGF(2 alpha) and PGE(2).