EFFECTS OF VOLATILE ANESTHETICS ON SODIUM/CALCIUM EXCHANGER ACTIVITY IN ISCHEMIC-REPERFUSION INJURY

研究了挥发性麻醉剂对缺血再灌注损伤大鼠钠钙交换器活性的影响。在这项研究中，我们检测了离体兔心室肌细胞的Na+/Ca+交换活性、Ca2+瞬态和收缩力。细胞内Na （[Na+]i）和Ca2+浓度（[Ca2+]i）分别用荧光Na指示剂sffl和fluo 3测量，并通过电场刺激下细胞缩短的变化来评估收缩性。实验在细胞外pH 7.4， HEPES缓冲液存在下进行。我们的研究结果表明：1)氟氯烷显著降低Ca2+瞬态和收缩性，2)缺血-再灌注引起[Ca2+] I和[Na+] I升高，3)氟氯烷减弱再灌注时[Ca2+] I升高的幅度，4)氟氯烷没有改变缺血时期[Na+] I的变化。提示氟烷引起的再灌注后细胞内过多钙的减少可能有利于兔完整心肌再灌注后的心肌功能。

We studied that effects of volatile anesthetics on sodium/calcium exchanger activity under ischemic-reperfusion injury. In this study, we examined Na+/Ca+ exchange activity, Ca2+ transients, and contractility in isolated rabbit ventricular myocytes. Intracellular Na ([Na+]i) and Ca2+ concentration ([Ca2+]i) were measured with the fluorescent Na indicators SBFL and fluo 3, respectively, and contractility was assessed from changes in cell shortening during field stimulation. Experiments were performed at extracellular pH 7.4 in the presence of HEPES buffer.Our findings demonstrate that I) halothane significantly decreased Ca2+ transients and contractility, 2) ischemic-reperfusion caused increases in [Ca2+]i and [Na+]i, 3) halothane attenuate the magnitude in increases in [Ca2+]i during reperfusion, 4) halothane did not alter the changes in [Na+]i during ischemic period.It is suggested that a reduction of excessive intracellular calcium after reperfusion caused by halothane may be beneficial on myocardial function following reperfusion in the intact rabbit myocardium.