5型磷酸二酯酶抑制剂对勃起功能障碍大鼠阴茎白膜病变的治疗作用

Therapeutic effect of phosphodiesterase-5 inhibitor on pathological changes of tunica albuginea in erectile dysfunction： experiment with rats

目的观察高脂、高胆固醇饮食诱导勃起功能障碍（ED）大鼠阴茎白膜的变化，明确长期小剂量给予5型磷酸二酯酶抑制剂（PDE-5I）他达拉非后的治疗作用，研究白膜组织在阴茎正常勃起过程中的作用及其意义。方法30只2月龄雄性SD大鼠随机分成3组，每组10只。对照组：喂以正常饮食16周；高脂组：喂以高脂、高胆固醇饮食（正常饮食中加入2％胆固醇＋10％猪油）16周；治疗组：在喂以高脂、高胆固醇饮食16周的基础上，从第13周起给予他达拉非2mg·kg^-1·d^-1灌胃1个月。各组大鼠经血脂测定后，测定海绵体内压及平均动脉压比值（ICP／MAP）以评估阴茎勃起功能，运用维多利亚蓝．丽春红对阴茎白膜弹力纤维染色，最后对标本进行显微镜图像分析。结果高脂组勃起功能（ICP／MAP：0．49±0．05）明显低于对照组（0．82±0．06，P〈0．01）；治疗组大鼠勃起能力（ICP／MAP：0．60±0．02）高于高脂组（P〈0．05）。高脂组白膜弹力纤维（468±152）明显低于对照组（3292±1123，P〈0．01），治疗组白膜弹力纤维（2062±560）高于高脂组（P〈0．05）。结论高脂、高胆固醇饮食可诱导大鼠发生ED，大鼠阴茎白膜弹力纤维减少是导致ED的机制之一，PDE-5I可以在一定程度上逆转这种变化。

Objective To investigate the pathological changes of tunica albuginea in erectile dysfunction （ED）, the role of tunica albuginea in penis erection, and the therapeutic effect of phosphediesterase-5 inhibitor （PDESI） on ED. Methods Thirty 8-week-old male Sprague-Dawley rats were randomly divided into 3 equal groups ： （ 1 ） control group fed with normal diet for 16 weeks, （2） high-fat group fed with the diet containing 2% cholesterol and 10% pork fat, and（3）Tadalafil group fed with high-fat diet for 16 weeks and undergoing gastric perfusion of Tadalafil 2 mg/kg daily since the 13th week for 4 weeks. Sixteen weeks later, intracavemous pressure and mean arterial pressure were measured, and the ratio of maximal intracavemous pressure to mean arterial pressure （ICP/MAP） was calculated blood samples were collected. Blood samples were collected from the abdominal aorta to undergo lipid profile test. Then penis was cut. Victoria blue/ponceau red staining and color image analysis were used to observe the content of elastic fibers in the tunica albuginea. Results The ICP/MAP of the high-fat group was 0. 49 ± 0. 05, significantly lower than that of the control group （0. 82 ±0. 06, P 〈0. 01 ）. The ICP/MAP of the Tadalafil group was 0. 60 ± 0. 02, significantly higher than that of the high-fat group （ P 〈 0. 05 ）. The content of elastic fibers in tunica albuginea of the high-fat group was 468 ± 152, significantly lower than that of the the control group （3292 ± 1123, P 〈0. 01 ）. The content of elastic fibers in tunica albuginea of the Tadalafil group was 2062 ± 560, significantly higher than that of the high-fat group （P 〈 0.05 ）. Conclusion High fat diet may lead to ED and reduction of elastic fibers in tunica albuginea, and PDE-SI reverses such pathological changes.