Endocrine Abstracts

In pigs, the assembly of primordial follicles and their subsequent transition to the primary stage occur in the late gestational and neonatal period. Previously, we reported the presence of androgen receptors in the porcine fetal ovary on different days of gestation, which suggests a fetus capacity to respond to androgens. Since testosterone was detected in the plasma of porcine female fetuses during the second half of pregnancy, it is possible that androgens are involved in prenatal folliculogenesis. Hence, we hypothesize that androgen deficiency during critical prenatal windows may alter expression of genes associated with ovarian development. Therefore, pregnant sows were injected with anti-androgen flutamide (50 mg/kg bw, seven times, every day) starting at day 43, 83 and 101 of gestation. Fetal ovaries were obtained on days 50, 90 and 108 of gestation, fixed in Bouin’s fixative for histology and immunohistochemistry or frozen in liquid nitrogen for real-time PCR analysis.

Immunohistochemistry was performed using a mouse monoclonal anti-Ki67 antibody (cell proliferation marker; dilution 1:75, Dako) or a goat polyclonal anti-GATA4 antibody (transcription factor involved in gonadal gene regulation; dilution 1:2000, Santa Cruz). Afterwards, to show Ki67 and GATA4 mRNA in the fetal porcine ovaries real-time PCR was carried out.

Immunohistochemical reaction revealed a higher number of proliferating cells in the fetal ovaries of flutamide-treated animals. Moreover, GATA4 expression has changed after flutamide exposure. Interestingly, prenatal antiandrogen administration resulted in GATA4 mRNA and protein up-regulation in the ovaries from days 50 and 108 of gestation, and their down-regulation on day 90 of gestation.

Our preliminary results suggest that diminished androgens action via blocking of androgen receptors leads to changes in the expression of genes crucial for ovarian development. It seems that androgens exhibit diverse biological actions depending on the gestational period.

Supported by a Grant No. N N303 596539.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This work was supported, however funding details unavailable.