Gajar Sessin A, Tano Tania, Resende Angela C, Bitencourt José Augusto F, de Lemos Neto Miguel, Damião Ronaldo, Criddle David N, Soares de Moura Roberto
Service of Urology, State University of Rio de Janeiro, Brazil.
BJU Int. 2007 Dec;100(6):1322-5. doi: 10.1111/j.1464-410X.2007.07260.x.
To investigate the effects of sildenafil on noradrenaline- and potassium-induced contractions of isolated human seminal vesicles (SVs), as premature ejaculation is a relatively common male sexual dysfunction that currently lacks an adequate therapy, and recent in vitro tests showed that sildenafil induces relaxation of rodent isolated SVs, but it is not known whether it also inhibits isolated human SV.
Isolated strips of human SVs were suspended in an organ bath and cumulative concentration-response curves to either noradrenaline or KCl were constructed in the presence and absence of sildenafil to evaluate its inhibitory actions.
Sildenafil (25-100 microm) induced concentration-dependent inhibitory effects on the human SV contracted by either noradrenaline or KCl. These actions of sildenafil do not therefore appear to be mediated via a competitive antagonism of alpha-adrenoceptors and are consistent with its recognized ability to inhibit phosphodiesterase-5.
The present results show an important inhibitory action of sildenafil in the isolated human SV, supporting the therapeutic indication of this drug for treating premature ejaculation.
早泄是一种相对常见的男性性功能障碍，目前缺乏有效的治疗方法，近期的体外试验表明西地那非可诱导啮齿动物离体精囊舒张，但尚不清楚其是否也能抑制人离体精囊。本研究旨在探讨西地那非对去甲肾上腺素和钾离子诱导的人离体精囊收缩的影响。
将人离体精囊条悬于器官浴槽中，在有和没有西地那非的情况下构建去甲肾上腺素或氯化钾的累积浓度-反应曲线，以评估其抑制作用。
西地那非（25 - 100微摩尔）对去甲肾上腺素或氯化钾诱导收缩的人离体精囊产生浓度依赖性抑制作用。因此，西地那非的这些作用似乎不是通过α-肾上腺素能受体的竞争性拮抗作用介导的，这与其公认的抑制磷酸二酯酶-5的能力一致。
目前的结果表明西地那非对人离体精囊具有重要的抑制作用，支持该药用于治疗早泄的治疗指征。
