The Expression of FSH Receptor (FSHR) in the Neonatal Porcine Ovary and its Regulation by Flutamide

Contents This study was designed to reveal the FSHR mRNA and protein expression in the neonatal porcine ovary and to determine whether maternal administration of antiandrogen flutamide may affect FSHR expression in the ovary of newborn piglets using real-time PCR, immunohistochemistry and Western blot analysis. Pregnant sows were injected with flutamide at a dose of 50 mg/kg body weight, given five times, every second day, starting at day 20 post-coitum (p.c.) or day 80 p.c., and ovaries were obtained from neonatal pigs. The FSHR mRNA expression was significantly decreased after flutamide administration. Furthermore, higher down-regulation was observed following exposure to antiandrogen at day 20 than at day 80 p.c. Immunohistochemistry showed the positive immunostaining for FSHR in the oocytes, granulosa cells of primary follicles and the surface epithelium of the ovaries from both control and flutamide-treated pigs. However, oocytes and granulosa cells of primary follicles in the ovaries exposed in utero to flutamide were weakly immunostained when compared to those in the control ones. The presence of FSHR protein in all investigated ovaries was confirmed by Western blot analysis. Based on our findings, we suggest that FSHR may be involved in the early follicle formation in pigs, which begins during prenatal life. Furthermore, the regulation of FSHR mRNA and protein expression in neonatal porcine ovaries after maternal exposure to flutamide confirms that androgens play a crucial role in porcine folliculogenesis at the early stages.