PGF2 alpha regulation of LH action on testicular testosterone production

PGF2 alpha has a reversible inhibitory effect on testicular T production in vitro and in vivo, while PGE2 is without effect. The PGF2 alpha effect is overcome by LH in a dose-dependent manner. Anti-LH has a similar effect as PGF2 alpha, the effects of both substances are not additive. Suppression of endogenous PG biosynthesis leads to potentiation of LH-stimulated T production in vitro but is without effect on basal T output. We conclude that PGF2 alpha inhibits testicular testosterone production by interfering with LH action on the Leydig cells. Histochemical studies indicate that PG synthesis in testes occurs mainly in the interstitial cells (4) and is probably androgen-dependent (5). Endogenous PGF2 alpha may therefore have a role in a local negative feedback regulation of LH action in testicular tissue.