【摘要】：目的:研究內(nèi)源性一氧化氮合酶(NOS)抑制物非對稱性二甲基精氨酸(ADMA)對豚鼠左心室流出道自律細胞電活動的影響,探討ADMA在源于心室流出道心律失常發(fā)生發(fā)展中的作用。方法:制備豚鼠離體左心室流出道標本,用氧飽和的改良Locke液進行恒溫、恒速灌流,采用標準玻璃微電極細胞內(nèi)電位記錄技術(shù)記錄豚鼠離體左心室流出道部位的自發(fā)慢反應(yīng)電位(sAP),觀測該電位對ADMA的濃度依賴性效應(yīng),ADMA分為3個濃度組(1、10和100μmol·L~(-1));用NO供體硝普鈉(SNP)灌流預(yù)處理標本,分為對照組、SNP(10μmol·L~(-1))組和SNP+ADMA組,記錄并分析SNP預(yù)處理對ADMA所致左心室流出道電生理效應(yīng)的影響。結(jié)果:與對照組比較,1μmol·L~(-1) ADMA組sAP各項指標均無明顯變化(P0.05),10和100μmol·L~(-1) ADMA組4相自動去極速度(VDD)、自發(fā)放電頻率(RPF)和0相最大除極速度(Vmax)明顯減慢(P0.05),復(fù)極50%和90%時間(APD50和APD90)明顯延長(P0.05),100μmol·L~(-1) ADMA組動作電位幅度(APA)明顯減小(P0.05);與1μmol·L~(-1) ADMA組比較,10μmol·L~(-1) ADMA組RPF、APD90及100μmol·L~(-1) ADMA組RPF、Vmax和APD50差異有統(tǒng)計學(xué)意義(P0.05);與10μmol·L~(-1) ADMA組比較,100μmol·L~(-1) ADMA組APA明顯減小(P0.05)。10μmol·L~(-1) SNP預(yù)處理標本10 min可逆轉(zhuǎn)ADMA降低左心室流出道自發(fā)放電活動的效應(yīng),與對照組比較,VDD和RPF仍明顯加快(P0.05),Vmax和APA有恢復(fù)至對照組水平的趨勢(P0.05),APD90明顯縮短(P0.05)。結(jié)論:內(nèi)源性NOS抑制物ADMA濃度依賴性降低左心室流出道自律細胞的自發(fā)放電活動,NO供體SNP預(yù)處理可逆轉(zhuǎn)上述效應(yīng)。
[Abstract]:Aim: to investigate the effect of asymmetric dimethyl arginine (ADMA), an endogenous nitric oxide synthase (NOS) inhibitor, on electrical activity in guinea pig left ventricular outflow tract (LVOT) autonomous cells, and to explore the role of ADMA in the development of ventricular outflow tract arrhythmias. Methods: the left ventricular outflow tract specimens of guinea pigs were prepared and perfused at constant temperature and at constant speed with oxygen-saturated modified Locke solution. The spontaneous slow response potential (SAP) of isolated left ventricular outflow tract of guinea pig was recorded by using standard glass microelectrode intracellular potential recording technique. The concentration-dependent effect of this potential on ADMA was observed. ADMA was divided into three concentration groups (1 / 10 and 100 渭 mol / L ~ (-1);). Body sodium nitroprusside (SNP) pretreated specimen, The rats were divided into control group (10 渭 mol L ~ (-1) and SNP-ADMA group. The effects of SNP pretreatment on the electrophysiological effects of ADMA-induced left ventricular outflow tract were recorded and analyzed. Results: compared with the control group, there were no significant changes in every index of AP in 1 渭 mol L ~ (-1) ADMA group (P0.05) and 100 渭 mol L ~ (-1) ADMA group (P0.05). The spontaneous discharge frequency (RPF) and the maximum depolarization velocity (Vmax) of 0 phase were significantly decreased (P0.05), and the repolarization 50% and 90% time (APD50 and APD90) were significantly decreased (APD50 and APD90). 鏄懼歡闀，

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