Mochizuki S, Seki S, Ejima M, Onodera T, Taniguchi M, Ishikawa S
Department of Internal Medicine, Aoto Hospital, Jikei University School of Medicine, Japan.
Mol Cell Biochem. 1993 Feb 17;119(1-2):151-7. doi: 10.1007/BF00926866.
The roles of the Na+/H+ exchange system in the development and cessation of reperfusion induced ventricular arrhythmias were studied in the isolated perfused rat heart. The hearts were perfused in the working heart mode with modified Krebs Henseleit bicarbonate (KHB) buffer and whole heart ischemia was induced by a one-way ball valve with 330 beat/min pacing. Ischemia was continued for 15 min followed by 20 min of aerobic reperfusion (control). Amiloride (1.0 mM), an inhibitor of the Na+/H+ exchange system, was added to the KHB buffer only during reperfusion (group B) or only during ischemic periods (group C). Electrocardiographic and hemodynamic parameters were monitored throughout the perfusion. Coronary effluent was collected through pulmonary artery cannulation and PO2, PCO2, HCO3- and pH were measured by blood-gas analyzer. The incidence of reperfusion induced ventricular arrhythmias was 100%, 100% and 0% in control, group B and group C, respectively. The mean onset time of termination of reperfusion arrhythmias was significantly shorter in group B than in control. PCO2 increased from 39.0 +/- 0.9 to 89.3 +/- 6.0 mmHg at the end of ischemia in control and from 40.6 +/- 0.4 to 60.5 +/- 5.8 in group C, the difference between groups was statistically significant. HCO3- level decreased from 21.8 +/- 0.1 to 18.3 +/- 0.5 mmol/l in control, however, this decrease was significantly inhibited in group C (from 22.0 +/- 0.5 to 20.3 +/- 0.2). The increase in PCO2 and the decrease in HCO3- in group B were similar over time to those observed in control.(ABSTRACT TRUNCATED AT 250 WORDS)
在离体灌注大鼠心脏中研究了钠氢交换系统在再灌注诱导的室性心律失常发生及终止过程中的作用。心脏在工作心脏模式下用改良的克雷布斯-亨泽莱特碳酸氢盐(KHB)缓冲液灌注,通过单向球阀以330次/分钟的起搏频率诱导全心缺血。缺血持续15分钟,随后进行20分钟的有氧再灌注(对照组)。钠氢交换系统抑制剂氨氯地平(1.0 mM)仅在再灌注期间(B组)或仅在缺血期间(C组)添加到KHB缓冲液中。在整个灌注过程中监测心电图和血流动力学参数。通过肺动脉插管收集冠状动脉流出液,并用血气分析仪测量PO2、PCO2、HCO3-和pH。对照组、B组和C组再灌注诱导的室性心律失常发生率分别为100%、100%和0%。B组再灌注心律失常终止的平均起始时间明显短于对照组。对照组缺血末期PCO2从39.0±0.9 mmHg增加到89.3±6.0 mmHg,C组从40.6±0.4 mmHg增加到60.5±5.8 mmHg,两组间差异有统计学意义。对照组HCO3-水平从21.8±0.1 mmol/l降至18.3±0.5 mmol/l,但在C组中这种下降受到显著抑制(从22.0±0.5 mmol/l降至20.3±0.2 mmol/l)。B组PCO2的增加和HCO3-的减少随时间变化与对照组相似。(摘要截断于250字)