Expressional Alternation of 5α-Reductase Type I, P450 Aromatase, and Androgen and Estrogen Receptors in the Mouse Testis Induced by the Lipectomy of the Epididymal Fat at Different Postnatal Ages

The epididymal fat is required for the maintenance of normal spermatogenesis, and the lipectomy of epididymal fat at different postnatal age results in disrupted expression patterns of several testicular steroidogenic enzymes. The current research examined the effect of epididymal fat lipectomy at different postnatal ages on expression of cytochrome 5α-reductase I, cytochrome P450 aromatase, androgen receptor (AR), and estrogen receptors (ER) α and β in the mouse testis after 2 weeks of the lipectomy. The lipectomy of epididymal fat at 2 months of postnatal age resulted in significant increases of expression levels of cytochrome 5α-reductase I, cytochrome P450 aromatase, AR, and ER α and β. However, expressions of these genes in the testis were significantly decreased by the lipectomy of epididymal fat at 5 months of postnatal age. The lipectomy of epididymal fat at 8 months and 12 months of postnatal ages did not influence expression levels of cytochrome 5α-reductase I, cytochrome P450 aromatase, AR, and ER β. However, a significant decrease of ER α was detected with the lipectomy of epididymal fat at 12 months of postnatal age. These observations suggest that expression of these genes in the testis by the influence of the epididymal fat is more susceptible at the earlier postnatal development than at the later postnatal period.