Inhibin production by rat early antral follicles in culture

VELASQUEZ ETHEL; CROXATTO HORACIO; ANDREONE LUZ; PARBORELL FERNANDA; ABRAMOVICH DALHIA; TESONE MARTA; CAMPO STELLA

Santiago, Chile.

Congreso; XIX Reunión Anual de la Sociedad Chilena de Ciencias Fisiológicas. II Simposio Latinoamericano de Interacción Materno-Fetal y Placenta (II SLIMP); 2005

Development and inhibin production by antral follicles is mainly dependent on FSH, which is a polymorphic hormone. Follicular synthesis of inhibin in vitro has not been reported. The aim of this study was to determine the effect of FSH glycosilated variants on production of inhibin, by rat early antral follicles (EAF) in culture. Methods: FSH variants bearing biantennary and truncated (WB) or high mannose and hybrid-type oligosaccharides (FB) were obtained after Con-A chromatography of recombinant human FSH (rhFSH). EAF (~350µm) were dissected from ovaries of Sprague-Dawley rats (23-25 day-old) treated with diethylstilbestrol. Follicles were cultured 37 C during 24 h in absence or presence of 25 ng/mL rhFSH or molecular variants. Following incubation, dimeric inhibin A and B and Pro-áC were assayed in the medium by ELISA. Results: Under basal conditions, follicles produced 4-fold more inhibin B than Inhibin A (A/B ratio = 0.32 ± 0.07). Inhibin A levels increased in response to rhFSH, WB and FB (P<0.05), although response to FB was significantly lower in comparison to WB (P<0.01). Addition of FSH at a dose of 25ng/mL failed to stimulate inhibin B production. Pro-aC levels were increased after treatment with WB and FB (P<0.05). Conclusions: These results show that rat EAF in culture produce and secrete inhibins, in similar proportion as observed in serum. Inhibin production was differentially stimulated by FSH variants.