【摘要】 目的　观察乙醇 (ethanol)对豚鼠离体心房肌生理特性的影响 ,并探讨其作用机制。方法　采用豚鼠左右离体心房测定ethanol对其自动节律、收缩力、功能不应期、静息后增强效应和正阶梯现象的影响。结果　ethanol(12 5 ,2 5 0 ,5 0 0 ,10 0 0 ,2 0 0 0mmol·L-1)明显降低豚鼠离体右心房肌的收缩力 ,同时减慢心率 ;ethanol(12 5 ,2 5 0 ,5 0 0 ,10 0 0 ,2 0 0 0mmol·L-1)抑制豚鼠离体左心房肌的收缩力 ,明显抑制左心房静息后增强效应 ;高浓度ethanol(10 0mmol·L-1、2 0 0mmol·L-1)延长左心房的功能不应期 ,并且抑制左心房正阶梯现象。结论　ethanol具有降低心房自律性、抑制心房肌收缩力、抑制左心房静息后增强效应、延长左心房功能不应期和抑制左心房正阶梯现象的作用 ,其负性变频和负性变力作用可能与抑制心肌细胞内贮钙的释放有关更多还原

【Abstract】 AIM To study the effects of ethanol on physiological characteristics of atria in isolated guinea pig. METHODS The effects of ethanol on contractility, spontaneous beat of right atrium, function refractory, post rest potentiation and positive staircase phenomenon were observed in isolated guinea pig left and right atria. RESULTS Ethanol(12 5, 25 0, 50 0, 100 0, 200 0 mmol·L -1 ) prominently inhibited the contractive force and decreased spontaneous beat of right atrium. Ethanol(12 5, 25 0, 50 0, 100 0, 200 0 mmol·L -1 ) inhibited the contractive force of left atrium, and markedly decreased the post rest potentiation of myocardial contractility in left atrium. Ethanol of high concentration(100?200 mmol·L -1 ) prolonged the function refractory period and depressed the positive staircase phenomenon of isolated guinea pig left atrium. CONCLUSION The ethanol induces inhibitory effects of the spontaneous beat, contractility, post rest potentiation, positive staircase phenomenon and prolonged the function refractory period. The mechanism by which ethanol induces the negative chronotropic and inotropic effects may be related to decreasing the amount of calcium released from intracellular stores.更多还原