EFFECTS OF VOLATILE ANESTHETICS ON PH ACTIVITY AND ISCHEMIC-REPERFUSION INJURY IN MYOCARDIAL CELLS

我们研究了挥发性麻醉药对缺血再灌注损伤心肌细胞pH活性的影响。在这项研究中，我们检测了分离的兔心室肌细胞的pH活性、钙瞬变和收缩性能。用荧光pH指示剂(BCFCE)、钠离子指示剂(SBFI)和钙离子指示剂(Fluo-3)分别测定细胞内H+浓度(Phi)、钠离子浓度([Na+]i)和钙离子浓度([Ca2+]i)。通过场刺激过程中细胞缩短的变化来评估收缩能力。实验在细胞外pH为7.4的HEPES缓冲液中进行。我们的研究结果表明：1)与异氟烷相比，氟烷显著降低心肌的收缩能力；2)氟烷和异氟烷可减缓再灌注期PHi的下降幅度；3)氟烷和异氟烷可减弱缺血期PHi的下降幅度。提示氟烷和异氟醚引起的再灌流后细胞内过量氢的减少可能对完整兔心肌再灌流后的心功能有利。

We studied the effects of volatile anesthetics on pH activity in myocardial cells during ischemic-reperfusion injury. In this study, we examined pH activity, Ca2+ transients, and contractility in isolated rabbit ventricular myocytes. Intracellular H+ concentration (pHi), Na+ concentration ([Na+]i) and Ca2+ concentration ([Ca2+]i) were measured with the fluorescent pH indicators (BCFCE), Na+ indicators (SBFI) and Ca2+ indicators (Fluo-3), respectively. 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 1) halothane significantly decreased contractility compared with isoflurane, 2) halothane and isoflurane attenuate the magnitude in decreases in pHi during reperfusion, 3) halothane and isoflurane attenuate the magnitude in decreases in pHi during ischemic period. It is suggested that a reduction of excessive intracellular hydrogen after reperfusion caused by halothane and isoflurane may be beneficial on myocardial function following reperfusion in the intact rabbit myocardium.