Sildenafil citrate (Viagra) is widely used for the treatment of erectile dysfunction with various etiologies. The aim of the present study was the investigation of histopathological effects of sildenafil citrate on rat corpus cavernosum using tight and electron microscopical techniques. Twenty male rats were divided into two groups. The first group (n = 10) was used as a control and the second group (n = 10) was treated with sildenafil citrate. Penile tissue was collected, fixed with formalin and embedded in paraffin for light microscopy, or fixed with gluteraldehyde and osmium tetroxide and embedded in Epon for electron microscopy. Light microscopical analysis showed that the corpus cavernosum was elongated and the number of blood vessels was increased. The amount of connective tissue in the penis was increased and dense collagen and smooth muscle fibers were observed in treated rats. Electron microscopical analysis showed that stromal structures of the corpus cavernosum (collagen fibers and number of cellular elements) were increased in treated rats. Fibroblasts showed signs of activation and the number of other stromal cells was increased. Immature newly synthesized collagen fibers were observed and penetrated endothelial basement membranes. In addition, endothelial cells also showed signs of activation such as cytoplasmic granules in treated rats, whereas the surface area of blood vessels was increased and basement membranes were thickened. These histopathological changes due to treatment with sildenafil citrate indicate that prolonged use of sildenafil citrate may increase the risk of fibrosis in the penis.

中文翻译：

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枸sil酸西地那非对大鼠海绵体的组织病理学影响。

枸酸西地那非（Viagra）被广泛用于治疗具有各种病因的勃起功能障碍。本研究的目的是使用紧密和电子显微镜技术研究柠檬酸西地那非对大鼠海绵体的组织病理学影响。将20只雄性大鼠分为两组。第一组（n = 10）用作对照，第二组（n = 10）用枸sil酸西地那非治疗。收集阴茎组织，用福尔马林固定并包埋在石蜡中进行光学显微镜检查，或用戊二醛和四氧化固定并包埋在Epon中进行电子显微镜检查。光学显微镜分析显示海绵体被拉长，血管数量增加。在治疗的大鼠中，阴茎中的结缔组织增加，并且观察到致密的胶原蛋白和平滑肌纤维。电子显微镜分析表明，在治疗的大鼠中海绵体的基质结构（胶原纤维和细胞元素的数量）增加了。成纤维细胞显示出激活的迹象，其他基质细胞的数量增加。观察到未成熟的新合成胶原纤维，并穿透了内皮基膜。另外，内皮细胞还显示出活化的迹象，例如在处理的大鼠中的细胞质颗粒，而血管的表面积增加并且基底膜增厚。