The Study Of Bone Marrow Mesenchymal Stem Cells Repairing Cavernous Nerve Injury Of Rats

Objective:This study is to explore the effects of transplantation of bone marrow mesenchymal stem cells on recovery of Sprague-Dawley rats'erectile function after bilateral cavernous nerve injury.Method:BM-MSCs were first established. We totally used 24 8-week-old male Sprague-Dawley (SD) rats and they were divided randomly into three groups. Rats in group one (Sham group) were treated with a sham operation without cavernous nerve manipulation. Rats in the other two groups were all treated with bilateral cavernous nerve injury (CNI). Rats in group one and group two (Crush group) were treated by injection with placebo while rats in group three (BM-MSCs group) were treated by injection with BM-MSCs in penis.8 weeks after the operation, erectile function was assessed by electrical stimulating cavernous nerve. We then collected the penile tissues for analysis of masson's trichrome, actin staining, immunofluorescence for NF-positive nerve fibers and neuronal nitric oxide synthase (nNOS) level and immunohistochemistry for neurotrophin-3 (NT-3) and neurotrophin-4 (NT-4) level.Results:After 8 weeks of nerve crushing, we evaluated the erectile function by stimulating cavernous nerve of rats. The results showed a lower mean maximal intracavernous pressure (ICP) in the BM-MSCs group, at (131.80±9.52) than that in the sham group, at 150.32±7.44) cmH2O. At the same time, the ICP in the BM-MSCs group was significantly higher than that in the crush group, at (100.48±5.97) cmH2O. Masson's trichrome showed that penis in the crush group had more serious fibrosis than that in BM-MSCs group. Actin staining showed that there were more smooth muscle fibers in the BM-MSCs group than in the crush group. Immunofluorescence technique showed an increasing number of NF-positive nerve fibers in the BM-MSCs group and that the nNOS in penile smooth muscle cells of the BM-MSCs group was increased. Immunohistochemistry results showed that both NT-3 and NT-4 were increased in the BM-MSCs group compared with that in the crush group and the sham group.Conclusion:Injection with BM-MSCs had beneficial effects on improving erectile function of CNI rats and increasing the content of smooth muscle fibers, NF-positive nerve fibers, nNOS, NT-3 and NT-4.