含不同浓度乳化异氟醚的停跳液对大鼠离体心脏缺血再灌注损伤的影响

目的 探讨含不同浓度乳化异氟醚的停跳液对大鼠离体心脏缺血再灌注损伤的影响.方法 清洁级雄性成年SD大鼠,体重180～250 g,建立Langendorff离体心脏灌注模型,取模型制备成功的56个心脏随机分为7组(n=8):St.Thomas停跳液组(C组)和含不同浓度乳化异氟醚的停跳液组(E1组～E6组).K-H液平衡灌注20 min后,C组用4℃ St.Thomas停跳液20 ml使心脏停搏45 min,K-H 液再灌注60 min,E1组～E6组分别用含乳化异氟醚0.28、0.56、1.12、1.68、2.24和2.80 mmol/L的4℃St.Thomas停跳液20 ml使心脏停搏45 min,K-H液再灌注60 min.于平衡灌注末、再灌注20、40、60 min 时记录HR、左心室发展压(LVDP)、左心室舒张末压(LVEDP)和左心室压力最大上升速率(+dp/dtmax),并收集冠脉流出液1.5 ml,测定乳酸脱氢酶(LDH)、超氧化物歧化酶(SOD)的活性和肌钙蛋白I(cTnI)浓度.于再灌注60 min时取心肌组织,计算心肌梗死面积.结果 与C组比较,E4组HR、LVDP、+dp/dtmax和SOD活性升高,LVEDP、LDH的活性和cTnI浓度降低,心肌梗死面积减小,E5组和E6组HR、LVDP、+dp/dtmax和SOD活性降低,LVEDP、LDH活性和cTnI浓度升高,心肌梗死面积增加(P<0.05),E1组～E3组上述指标差异无统计学意义(P>0.05).与E4组比较,其余含不同浓度乳化异氟醚的停跳液组HR、LVDP、+dpldt～和SOD活性降低,LVEDP、LDH活性和cTnI浓度升高,心肌梗死面积增加(P<0.05).结论 含1.68 mmol/L乳化异氟醚的停跳液可减轻大鼠离体心脏缺血再灌注损伤.

Effects of cardioplegic solution containing different concentrations of emulsified isoflurane on myocardial ischemia-reperfusion injury in isolated rat hearts

Objective To investigate the effects of cardioplegic solution containing different concentrations of emulsified isoflurane on myocardial ischemia-reperfusion injury in isolated rat hearts. Methods Fifty-six male SD rats, weighing 180-250 g, were anesthetized with intraperitoneal 20% urethane 1 g/kg and heparin 1 000 U/kg. Their hearts were excised and perfused in a Langendorff apparatus. Fifty-six isolated hearts were randomly divided into 7 groups ( n = 8 each) : St. Thomas cardioplegic solution group (group C) and St. Thomas cardioplegic solution containing 6 different concentrations of emulsified isoflurane groups (group E1-6 ). After 20 min equilibration, cardiac arrest was induced with St. Thomas cardioplegic solution 20 ml and St. Thomas cardioplegic solution containing 0.28, 0.56, 1.12, 1.68, 2.24 and 2.80 mmol/L emulsified isoflurane 20 ml at 4℃for 45 min followed by 60 min reperfusion in group C and E1-6 respectively. HR, left ventricular developed pressure (LVDP), left ventricular end-diastolic pressure (LVEDP) and + dp/dtmax were recorded at the end of 20 min equilibration, 20, 40 and 60 min of reperfusion. Coronary effluent 1.5 ml was collected for determination of LDH and SOD activity and the concentration of cTnI. At the end of 60 min reperfusion, the area of myocardial infarction was calculated. Results Compared with group C, HR, LVDP, + dp/dtmax and SOD activity were significantly higher, LVEDP, LDH activity and cTnI concentration lower, and the area of myocardial infarction lower in group E4, and HR, LVDP, + dp/dtmax and SOD activity were significantly lower, LVEDP, LDH activity and cTnI concentration higher, and the area of myocardial infarction higher in group E6 and E6 ( P < 0.05) , but there was no significant difference in the above indices between group E1-3 and group C ( P > 0.05) . HR, LVDP, + dp/dtmax and SOD activity were significantly lower, LVEDP, LDH activity and cTnI concentration higher, and the area of myocardial infarction higher in group E1-3-5-6 than in group E4 (P < 0.05 ). Conclusion St. Thomas cardioplegic solution containing 1.68 mmol/L emulsified isoflurane can attenuate myocardial ischemia-reperfusion injury in isolatede rat hearts.