Effects of ethanol on the tonicity of corporal tissue and the intracellular Ca^2＋ concentration of human corporal smooth muscle cells  

作　　者：Sung Chul Kam Mee Ree Chae Ji Young Kim Seol Ho Choo Deok Hyun Han Sung Won Lee 

机构地区：[1]Department of Urology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, Korea

出　　处：《Asian Journal of Andrology》2010年第6期890-898,共9页亚洲男性学杂志（英文版）

摘　　要：Heavy alcohol consumption is associated with an increased risk of erectile dysfunction （ED）; however, the acute effects of ethanol （EtOH） on penile tissue are not fully understood. We sought to investigate the effects of EtOH on corporal tissue tonicity, as well as the intracellular Ca^2＋ concentration （[Ca^2＋]i） and potassium channel activity of corporal smooth muscle. Strips of corpus cavernosum （CC） from rabbits were mounted in organ baths for isometric tension studies. Electrical field stimulation （EFS） was applied to strips precontracted with 10 μmol L^-1 phenylephrine as a control. EtOH was then added to the organ bath and incubated before EFS. The [Ca^2＋]i levels were monitored by the ratio of fura-2 fluorescence intensities using the fura-2 loading method. Single-channel and whole-cell currents were recorded by the conventional patch-clamp technique in short-term cultured smooth muscle cells from human CC tissue. The corpus cavernosal relaxant response of EFS was decreased in proportion to the concentration of EtOH. EtOH induced a sustained increase in [Ca^2＋]i in a dose-dependent manner, Extracellular application of EtOH significantly increased whole-cell K^＋ currents in a concentration-dependent manner （P 〈 0.05）. EtOH also increased the open probability in cell-attached patches; however, in inside-out patches, the application of EtOH to the intracellular aspect of the patches induced slight inhibition of Ca^2＋-activated potassium channel （KCa） activity. EtOH caused a dose-dependent increase in cavemosal tension by alterations to [Ca^2＋]i. Although EtOH did not affect KCa channels directly, it increased the channel activity by increasing [Ca^2＋]i. The increased corpus cavemosal tone caused by EtOH might be one of the mechanisms of ED after heavy drinking.Heavy alcohol consumption is associated with an increased risk of erectile dysfunction （ED）; however, the acute effects of ethanol （EtOH） on penile tissue are not fully understood. We sought to investigate the effects of EtOH on corporal tissue tonicity, as well as the intracellular Ca^2＋ concentration （[Ca^2＋]i） and potassium channel activity of corporal smooth muscle. Strips of corpus cavernosum （CC） from rabbits were mounted in organ baths for isometric tension studies. Electrical field stimulation （EFS） was applied to strips precontracted with 10 μmol L^-1 phenylephrine as a control. EtOH was then added to the organ bath and incubated before EFS. The [Ca^2＋]i levels were monitored by the ratio of fura-2 fluorescence intensities using the fura-2 loading method. Single-channel and whole-cell currents were recorded by the conventional patch-clamp technique in short-term cultured smooth muscle cells from human CC tissue. The corpus cavernosal relaxant response of EFS was decreased in proportion to the concentration of EtOH. EtOH induced a sustained increase in [Ca^2＋]i in a dose-dependent manner, Extracellular application of EtOH significantly increased whole-cell K^＋ currents in a concentration-dependent manner （P 〈 0.05）. EtOH also increased the open probability in cell-attached patches; however, in inside-out patches, the application of EtOH to the intracellular aspect of the patches induced slight inhibition of Ca^2＋-activated potassium channel （KCa） activity. EtOH caused a dose-dependent increase in cavemosal tension by alterations to [Ca^2＋]i. Although EtOH did not affect KCa channels directly, it increased the channel activity by increasing [Ca^2＋]i. The increased corpus cavemosal tone caused by EtOH might be one of the mechanisms of ED after heavy drinking.

关 键 词：ALCOHOL Ca^2＋-activated potassium channel corporal smooth muscle penile erection 

分 类 号：Q492[生物学—生理学] TS262.2[轻工技术与工程—发酵工程]