Endocrine Abstracts

3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (HSD3B) is a key enzyme catalyzing an essential step in the formation of all classes of steroid hormones. Previously, we have reported the presence of androgen receptors in the fetal porcine gonads denoting the role of androgens during gonadal development. There is also growing evidence that steroid hormones modulate HSD3B expression. Thus, the aim of the present study was to determine the effect of androgen deficiency during late prenatal period on HSD3B expression in the fetal porcine gonads.

Pregnant sows were injected with anti-androgen flutamide (50 mg/kg bw, seven times, every day) starting at gestational day (GD) 83 or 101. The fetal gonads were obtained on GD90 or GD108. HSD3B immunolocalization was performed using rabbit polyclonal anti-mouse HSD3B antibody (provided by Prof. A H Payne from Stanford University). To assess HSD3B mRNA expression real-time PCR was carried out using the TaqMan Gene Expression Assay (Applied Biosystems).

In testes from control and flutamide-exposed fetuses, HSD3B was immunolocalized in Leydig cells. Following flutamide treatment, the number of HSD3B positive Leydig cells was higher on GD90 and lower on GD108 vs control. Moreover, flutamide administration resulted in increased HSD3B mRNA expression on GD90 and decreased HSD3B mRNA expression on GD108.

In ovaries from control and flutamide-exposed fetuses, HSD3B was immunolocalized in granulosa cells of forming follicles. Following flutamide administration, increased expression of HSD3B mRNA and protein were observed on GD90. However on GD108, flutamide treatment led to decreased HSD3B mRNA expression, while no changes in the intensity of immunostaining were observed.

In summary, diminished androgen action in porcine fetal gonads during late gestation induce changes in HSD3B expression, which may result in functional changes in Leydig or granulosa cells. However, it seems that androgens exert diverse biological effects depending on the gestational period.

Supported by Iuventus Plus grant (IP2011 024571).