Department of Urology, College of Medicine, The Catholic University of Korea, Seoul, Korea.
Int J Impot Res. 2010 Sep-Oct;22(5):291-7. doi: 10.1038/ijir.2010.19. Epub 2010 Sep 23.
Impotence is one of the common complications after the radical prostatectomy. One of the main reasons of this complication is due to the dysfunction of the veins in corpus cavernosum. Recent studies have shown that the erectile function is improved after the long-term therapy of phosphodiesterase type 5 inhibitor among patients with post-prostatectomy erectile dysfunction. In this study, we evaluated the effects of mirodenafil on the penile erection and corpus cavernosum tissues in the rat model of cavernosal nerve injury. Rats were divided into four groups: (1) control group, (2) bilateral cavernosal nerve injury group, (3) mirodenafil 10 mg therapy group after the nerve injury and (4) mirodenafil 20 mg therapy group after the nerve injury. After we identified the nerve from the pelvic nerve complex on the lateral side of the prostate, the rats in the control group were sutured without causing any nerve injury and in other groups we damaged the nerve by compressing it with a vessel clamp. Then, 10 and 20 mg kg(-1) of mirodenafil were orally administered to two experimental groups. After 8 weeks, the intracavernosal pressure (ICP) was recorded. The immunohistochemical staining and western blot were performed, and the effect of mirodenafil on the expression of cyclic guanosine monophosphate (cGMP) was evaluated through enzyme-linked immunosorbent assay. The ICP of nerve-injured group was decreased compared with the control group; however, the ICP of the mirodenafil-administered groups was improved compared with the nerve-injured group. The Masson's trichrome staining confirmed that the smooth muscle (SM) component was increased in the mirodenafil-administered groups. The nitric oxide synthase expression and cGMP of mirodenafil-administered groups was increased compared with the nerve-injured group. Long-term therapy of mirodenafil may improve the erectile function after the radical prostatectomy by preserving the SM content and inhibiting the fibrosis of the corpus cavernosum.
勃起功能障碍是根治性前列腺切除术后的常见并发症之一。这种并发症的主要原因之一是由于海绵体静脉功能障碍。最近的研究表明，在前列腺切除术后勃起功能障碍患者中，长期应用磷酸二酯酶 5 抑制剂治疗可以改善勃起功能。在这项研究中，我们评估了米罗那非对海绵体神经损伤大鼠模型阴茎勃起和海绵体组织的影响。大鼠分为四组：（1）对照组，（2）双侧海绵体神经损伤组，（3）神经损伤后给予米罗那非 10mg 治疗组，（4）神经损伤后给予米罗那非 20mg 治疗组。在从前列腺侧方的盆神经丛中识别出神经后，对照组大鼠仅进行缝合而不造成任何神经损伤，而在其他组中，我们用血管夹压迫神经造成损伤。然后，两组实验组大鼠分别给予 10 和 20mg/kg 的米罗那非口服治疗。8 周后，记录海绵体内压（ICP）。进行免疫组织化学染色和 Western blot 分析，并通过酶联免疫吸附试验评估米罗那非对环鸟苷酸（cGMP）表达的影响。与对照组相比，神经损伤组的 ICP 降低；然而，给予米罗那非的两组的 ICP 均较神经损伤组改善。Masson 三色染色证实，米罗那非给药组的平滑肌（SM）成分增加。与神经损伤组相比，米罗那非给药组的一氧化氮合酶表达和 cGMP 增加。长期应用米罗那非可能通过保留 SM 含量和抑制海绵体纤维化来改善根治性前列腺切除术后的勃起功能。
