Department of Urology, Gil Medical Center, Gachon University, #1198 Guwol-dong, Namdong-gu, Incheon 405-760, Republic of Korea.
J Biomed Sci. 2013 Oct 25;20(1):81. doi: 10.1186/1423-0127-20-81.
Tamsulosin, an α1-adrenoceptor antagonist, and sildenafil, a phosphodiesterase (PDE) inhibitor, are reported to improve lower urinary tract symptoms including overactive bladder (OAB). This study is aimed at investing the effects of tamsulosin and sildenafil and comparing the degree of the suppressive effects on the afferent pathways of micturition between them using an animal model of OAB, the spontaneously hypertensive rat (SHR).
The cystometric parameters, the basal pressure and duration of bladder contraction, were significantly increased in the SHR group as compared with the Wistar-Kyoto (WKY) group. The intercontraction interval also significantly decreased in the SHR group. In the SHR-Tam 0.01 mg/kg group and the SHR-Sil 1 mg/kg group, however, the basal pressure and duration were significantly reduced and the intercontraction interval was significantly prolonged. Moreover, the degree of the expression of c-Fos and NGF was significantly higher in the SHR group as compared with the WKY group. But it was significantly reduced in the SHR-Tam 0.01 mg/kg group and the SHR-Sil 1 mg/kg group. Furthermore, tamsulosin had a higher degree of effect as compared with sildenafil.
In conclusion, α1-adrenergic receptor antagonists and PDE-5 inhibitors may have an effect in improving the voiding functions through an inhibition of the neuronal activity in the afferent pathways of micturition.
坦索罗辛是一种α1-肾上腺素受体拮抗剂，西地那非是一种磷酸二酯酶（PDE）抑制剂，据报道它们可改善下尿路症状，包括膀胱过度活动症（OAB）。本研究旨在通过一种 OAB 动物模型，自发性高血压大鼠（SHR），研究坦索罗辛和西地那非的作用，并比较它们对排尿传入通路的抑制作用程度。
与 Wistar-Kyoto（WKY）组相比，SHR 组的膀胱测压参数、基础压和膀胱收缩持续时间明显增加，收缩间期也明显缩短。然而，在 SHR-Tam 0.01mg/kg 组和 SHR-Sil 1mg/kg 组中，基础压和持续时间明显降低，收缩间期明显延长。此外，与 WKY 组相比，SHR 组的 c-Fos 和 NGF 表达水平明显升高，但在 SHR-Tam 0.01mg/kg 组和 SHR-Sil 1mg/kg 组中明显降低。此外，坦索罗辛的作用程度高于西地那非。
综上所述，α1-肾上腺素受体拮抗剂和 PDE-5 抑制剂可能通过抑制排尿传入通路的神经元活性来改善排尿功能。
