Expression Of VDR In Sheep Testis And Epididymis & The Effect Of Vitamin D On Sheep Epididymis Cells

[Objective] Vitamin D is a kind of steroid hormone that plays important roles for animal health through the biologically active form 1α,25-dihydroxy-vitamin D3 (1α,25-(OH)2D3). 1α,25-(OH)2D3 regulates many physiological functions, such as calcium homeostasis, bone metabolism, cell differentiation and proliferation with the help of vitamin D recepter (VDR). However, the effect of 1α,25-(OH)2D3 on epididymis is not clear. The objectives of present study were to investigate the presence of VDR in epididymis of ram, to explore the effect of la,25-(OH)2D3 on cell viability, proliferation, apoptosis, antioxidant capacity and secretory function of ram epididymis cells.[Method] The study used techniques as PCR, immunohistochemical, Real-time PCR, Western blotting, to observe the expression of VDR on testis and caput, corpus, cauda of epididymis; caput, corpus, cauda of epididymis cell were exposured in different concentration of 1α,25-(OH)2D3, then applied methods as cell count, Real-time PCR, enzyme immuno sandwich assay, to test cell viability; proliferation; the expression of p53、bax、bcl-2 genes; the capacity of total antioxidant, catalase, superoxide dismutase, glutathione peroxidase, glutathione S transferase; the secretion of α-1,4-glycosidase, sialic acid, lactoferrin of caput, corpus and cauda epididymis cells.[Result] (1) This study found that VDR existed in caput, corpus and cauda epididymis cells, Leydig cells, spermatogonial stem cells, spermatocytes, Sertoli cells and principal cells of testis; the contents of VDR mRNA and VDR protein in caput, corpus and cauda epididymis were higher than in testis;(2) 1α,25-(OH)2D3 promoted the cell viability; proliferation; total antioxidant capacity, catalase capacity, superoxide dismutase capacity, glutathione peroxidase capacity, glutathione S transferase capacity; the secretion of sialic acid and lactoferrin of caput, corpus and cauda epididymis cells(P<0.01/P<0.05). However, 1α,25-(OH)2D3 had no effect on the expression of p53、bax、bcl-2 genes and the secretion of α-1,4-glycosidase.[Conclusion] In conclusion, VDR exists in testis and epididymis of ram, 1α,25-(OH)2D3 improves the fuction of epididymis cell, suggesting 1α,25-(OH)2D3 may improve the semen quality indirectly.