Effects of phosphodiesterase 5 inhibitors on sperm parameters and fertilizing capacity

作     者：F. Dimitriadis D. Giannakis N. Pardalidis K. Zikopoulos E. Paraskevaidis N. Giotitsas V. Kalaboki P.Tsounapi D. Baltogiannis Georgiou M.Saito T.Watanabe I. Miyagawa N.Sofildtis 

作者机构：Laboratory of Molecular Urology and Genetics of Human Reproduction Department of Urology Ioannina University School of Medicine Ioannina 45110 Greece Department of Urology Tottori University School of Medicine Yonago 683 Japan 

出 版 物：《Asian Journal of Andrology》 (亚洲男性学杂志（英文版）)

年 卷 期：2008年第10卷第1期

页      面：115-133页

核心收录：

学科分类：1002[医学-临床医学] 100210[医学-外科学(含：普外、骨外、泌尿外、胸心外、神外、整形、烧伤、野战外)] 10[医学] 

主　　题：sperm fertilizing capacity phosphodiesterase 5 inhibitors spermatozoa testis male infertility 

摘      要：The aim of this review study is to elucidate the effects that phosphodiesterase 5 （PDE5） inhibitors exert on spermatozoa motility, capacitation process and on their ability to fertilize the oocyte. Second messenger systems such as the cAMP/adenylate cyclase （AC） system and the cGMP/guanylate cyclase （GC） system appear to regulate sperm functions. Increased levels of intracytosolic cAMP result in an enhancement of sperm motility and viability. The stimulation of GC by low doses of nitric oxide （NO） leads to an improvement or maintenance of sperm motility, whereas higher concentrations have an adverse effect on sperm parameters. Several in vivo and in vitro studies have been carried out in order to examine whether PDE5 inhibitors affect positively or negatively sperm parameters and sperm fertilizing capacity. The results of these studies are controversial. Some of these studies demonstrate no significant effects of PDE5 inhibitors on the motility, viability, and morphology of spermatozoa collected from men that have been treated with PDE5 inhibitors. On the other hand, several studies demonstrate a positive effect of PDE5 inhibitors on sperm motility both in vivo and in vitro. In vitro studies of sildenafil citrate demonstrate a stimulatory effect on sperm motility with an increase in intracellular cAMP suggesting an inhibitory action of sildenafil citrate on a PDE isoform other than the PDE5. On the other hand, tadalafil＇s actions appear to be associated with the inhibitory effect of this compound on PDE11. In vivo studies in men treated with vardenafil in a daily basis demonstrated a significantly larger total number of spermatozoa per ejaculate, quantitative sperm motility, and qualitative sperm motility; it has been suggested that vardenafil administration enhances the secretory function of the prostate and subsequently increases the qualitative and quantitative motility of spermatozoa. The effect that PDE5 inhibitors exert on sperm parameters may lead to the impr