Seasonal changes in the expression of PACAP, VPAC1, VPAC2, PAC1 and testicular activity in the testis of the muskrat ( < em > Ondatra zibethicus < /em > )

In this study, we investigated the seasonal expressions of PACAP, PAC1, VPAC1, VPAC2, luteinizing hormone receptor (LHR), follicle stimulating hormone receptor (FSHR), steroidogenic acute regulatory protein (StAR), 3 β-hydroxysteroid dehydrogenase (3β-HSD), and CYP17A1 in the testis of the male muskrat during the breeding season and the non-breeding season. Histologically, we found the presence of Leydig cells, Sertoli cells and all kinds of germ cells in the testis during the breeding season but only Leydig c ells, Sertoli cells, spermatogonia and primary spermatocyte during the non-breeding season. The immunohistochemical localizations of PACAP and VPAC1 were identified in the Leydig cells, spermatogonia and spermatozoa during the breeding season while only in Leydig cells and spermatogonia during the n on-breeding season, and PAC1 and VPAC2 were localized in the Leydig cells in both seasons, in which LHR, StAR, 3β-HSD and CYP17A1 were also expressed. Meanwhile, protein and mRNA expression levels of PACAP, PAC1, VPAC1, VPAC2, LHR, FSHR, StAR, 3β-HSD and CYP17A1 in the testis during the breeding s eason were significantly higher than those during the non-breeding season. These results suggested that PACAP may involve in the regulation of, steroidogenesis and spermatogenesisvia an endocrine, autocrine or paracrine manner in the testis of the muskrat.
Source: European Journal of Histochemistry - Category: Biomedical Science Authors: Source Type: research