Cavalcanti Andre G, Yucel Selcuk, Deng Donna Y, McAninch Jack W, Baskin Laurence S
Department of Urology and Pediatrics, University of California-San Francisco Children's Medical Center, University of California-San Francisco, 94143, USA.
J Urol. 2004 May;171(5):1943-7. doi: 10.1097/01.ju.0000121261.03616.63.
The distribution of neuronal (n) and inducible (i) nitric oxide synthase (NOS) may have a role in the maintenance of normal urethral spongiosum and during the development of spongiofibrosis in urethral stricture disease.
Eight normal and 33 strictured human bulbar urethras were studied by histological and immunohistochemical techniques for the neuronal markers S-100, nNOS and iNOS. The smooth muscle-to-collagen ratio was calculated by morphometric analysis of Masson's trichrome sections. Immunohistochemical staining patterns of the neuronal markers in normal urethral tissue was compared to that in urethral stricture tissue with spongiofibrosis.
The smooth muscle-to-collagen ratio was significantly lower in the strictured urethra compared to that in the control group (p = 0.001). In the strictured bulbar urethra nNOS immunoreactivity was decreased compared to that in normal urethral tissue. The severity of spongiofibrosis corresponded to the loss of nNOS immunoreactivity. iNOS immunoreactivity was found in strictured urethral epithelium and spongiosal tissue, whereas the control group was nonimmunoreactive to iNOS.
Urethral stricture formation is a fibrotic process associated with significant changes in NOS metabolism. Abnormal collagen synthesis following urethral trauma may be stimulated by inappropriate iNOS activity. A functional nerve supply to the urethral spongiosum seems to be crucial in the maintenance of the unique ultrastructure of the urethral spongiosum.
神经元型（n）和诱导型（i）一氧化氮合酶（NOS）的分布可能在维持正常尿道海绵体以及尿道狭窄疾病海绵体纤维化发展过程中发挥作用。
采用组织学和免疫组织化学技术，对8例正常人类球部尿道和33例狭窄球部尿道进行神经元标志物S-100、nNOS和iNOS研究。通过对Masson三色染色切片进行形态计量分析，计算平滑肌与胶原的比例。将正常尿道组织中神经元标志物的免疫组织化学染色模式与伴有海绵体纤维化的尿道狭窄组织中的模式进行比较。
与对照组相比，狭窄尿道的平滑肌与胶原比例显著降低（p = 0.001）。与正常尿道组织相比，狭窄球部尿道中nNOS免疫反应性降低。海绵体纤维化的严重程度与nNOS免疫反应性的丧失相对应。在狭窄尿道上皮和海绵体组织中发现iNOS免疫反应性，而对照组对iNOS无免疫反应。
尿道狭窄形成是一个与NOS代谢显著变化相关的纤维化过程。尿道创伤后异常的胶原合成可能由不适当的iNOS活性刺激引起。尿道海绵体的功能性神经供应似乎对维持尿道海绵体独特的超微结构至关重要。
