The Establishment Of Erectile Dysfunction Following Spinal Cord Injury Rat Model And Its Mechanism Research

Objective: To establish the feasibility of the establishment of the erectile dysfunctionfollowing spinal cord injury rat model by the method of modified Allen and explore itspathogenesis.Methods: Sixty male adult SD rats were randomly divided into experimental group(n=25,Spinal cords were exposed and destroyed), control group（n=25, Spinal cords wereexposed but not destroyed）and normal group(n=10, Spinal cords were neither exposed nordestroyed). The erectile dysfunction following incomplete spinal cord injury model wasinduced by using modified Allen method. Three weeks later, the time to first response(TFR), the number of yawns and erectile frequency induced by apomorphine(APO)within30minites (EF30) were evaluated and recorded.The electron ultrastructures of the corpuscavernosum smooth muscle cells(CCMCs) were observed with transmission electronmicroscope; the expression of nNOS in the rat,s penis corpora cavernosa tissue wasexamined by the method of immunohistochemical staining.Results: In APO experiment, TFR and EF30were decreased significantly compared withcontrol group and normal group(P＜0.05), but the number of yawns showed no obviousdifference between the three groups(P＞0.05). Electron microscopy showed that comparedwith the control group and normal group，the numbers of mitochondria in the cytoplasmand caveolae with fingerlike processes in the plasma membrane were significantly less, butthe number of vacuoles in the cytoplasm was increased. The positive rate of nNOS in therats penis corpora cavernosa tissue was lower than the control group and normal group（P＜0.05）. Conclusion: The results showed that this model has more stability and similarity withclinic and it can well reflect the conditions of erectile dysfunction following spinal cordinjury. The modified Allen method was suitable for the construction of erectile dysfunctionfollowing spinal cord injury. In the occurrence of ED, the changes of ultrastructures andthe low expression level of nNOS in penis tissue play important roles.