A NOVEL NEUROPEPTIDE CELLULAR MECHANISM IN AMPHIBIAN INTERRENAL STEROIDOGENESIS

Interrenals of female Rana esculenta were incubated with gonadotropin- releasing hormone (GnRH), 9-ketoreductase inhibitor (palmitic acid), a cetyl salicyclic acid, prostaglandin F-2 alpha, (PGF(2 alpha)), forsko lin, isobutylmethyl xanthine (IBMX), dibutyril cyclic adenosine monoph osphate (dbcAMP). Prostaglandin E(2) (PGE(2)), PGF(2 alpha), testoster one and 17 beta-estradiol were assessed on the incubation media. In ad dition, in the same interrenals, 9-ketoreductase and aromatase activit ies were evaluated. GnRH increased PGF(2 alpha), 17 beta-estradiol, 9- ketoreductase and aromatase, and decreased PGE(2) and testosterone. PG F(2 alpha) increased 17 beta-estradiol and aromatase, and decreased te stosterone. Palmitic acid counteracted GnRH effects, while forskolin, IBMX and dbcAMP showed the same PGF(2 alpha) effects. These results su ggest that GnRH stimulates 9-ketoreductase enhancing PGF(2 alpha) whic h in turn activates aromatase through cAMP mediation in the interrenal of Rana esculenta.