缺血后处理与心肌保护

随着心脏外科手术和介入治疗的增加，人们越来越重视其中的主要病理生理过程——心肌缺血再灌注损伤（myocardium ischemic-reperfusion injury，MIRI）。MIRI是指心肌缺血一定时间后即使恢复血液灌注，仍将引起心肌功能障碍和结构损害，表现为致死性再灌注损伤、心肌顿抑、心律失常和能量代谢改变。其发病机制仍未完全阐明，通常认为与氧自由基、钙超载、中性粒细胞、微血管损伤和能量代谢障碍等有关。近年来对其发生机制和防治方法的研究越来越深入，发现缺血后处理（ischemic postconditioning，IPO）。有很好的心肌保护作用。现就IPO对心肌缺血和再灌注损伤的保护作用、可能机制及其意义作一综述。     

参附注射液对大鼠缺血再灌注心肌Bcl-2、Bax与c-fos基因蛋白表达的影响

目的 观察大鼠急性缺血再灌注损伤与凋亡相关基因Bcl-2、c-fos和Bax蛋白表达的关系及参附注射液(SF)的影响.方法 采用整体缺血再灌注(ischemia-reperfusion,IR)模型,35只大鼠分为假手术组(C组)、生理盐水30 min对照组(IR 30)、生理盐水120 min对照组(IR 120)、SF 30 min组(SF 30)和SF 120 min组(SF 120),心肌缺血40 min再灌注30 min或120 min后,用免疫组化法检测Bcl-2、Bax和c-fos在心肌中的表达量.结果 与C组比较,IR组心肌Bcl-2、Bax和c-fos蛋白表达显著升高(P＜0.01),Bcl-2/Bax比值显著下降(P＜0.01);与IR组比较,SF组Bcl-2蛋白表达显著升高(P＜0.01),Bax和c-fos蛋白表达显著降低(P＜0.01),Bcl-2/Bax比值显著升高(P＜0.01).结论 SF对IR心肌保护效应可能与其促进Bcl-2蛋白高表达、抑制Bax与c-fos蛋白表达、增加Bcl-2/Bax比值,从而抑制心肌细胞凋亡有关.     

凋亡因子bcl-2/bax与心肌缺血再灌注损伤

缺血再灌注损伤是心脏缺血性疾病的一个常见的病理生理过程,细胞凋亡是心肌细胞的一种程序性死亡.研究表明,凋亡因子bcl-2和bax的相互作用是细胞凋亡的调控中心,因此研究凋亡因子bcl-2/bax在心肌缺血再灌注损伤中的作用及其机制,并从基因水平采取相应调节措施来防治心肌细胞缺血再灌注损伤,将具有深远的理论意义和临床应用前景.现就凋亡因子bcl-2/bax在心肌细胞缺血再灌注损伤方面的作用及研究进展作一综述.     

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

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.     

镁对心肌缺血再灌注损伤的保护作用

在再灌注之前或同时应用细胞保护剂,是防治或减轻心肌缺血再灌注损伤的主要措施.Mg2 是体内300多种酶的辅酶,具有多种生理功能.近年研究表明,镁制剂作为细胞保护剂应用于再灌注损伤,可发挥良好的心肌保护作用.现就镁在心肌缺血再灌注IR损伤中的保护作用及其作用机制以及在AMI方面的临床应用情况综述如下.     

麻醉学专业本科生临床实习的带教体会

我国现阶段的麻醉学专业教育总体上仍处于探索和完善阶段,如何培养出较高素质的麻醉学专业医学生是医学教育和麻醉学教学的新问题。笔者根据2003～2005年临床实习带教实践经验,就如何做好该专业本科生临床实习的带教工作谈谈自己的体会。     

静脉乳化异氟醚的研究进展

直接静脉注射挥发性吸入麻醉药可导致动物或人的组织器官严重损害甚至死亡,而乳化挥发性吸入麻醉药可产生良好的麻醉作用且不良反应小。乳化异氟醚作为一种新型的静脉全麻药,直接静脉注射可获得确切的可逆性麻醉作用,其MAC静脉相似文献   

无痛纤维支气管镜检查中的麻醉管理的研究进展

我国20世纪70年代初始开展纤维支气管镜检查,至今已发展为确诊及治疗某些呼吸系统疾病的首选方法,已在临床实践中得到广泛应用。传统的纤维支气管镜检查方法是采用局部表面麻醉,患者在清醒状态下接受检查,易致患者出现生理、心理不适,使患者承受巨大痛苦;而无痛纤维支气管镜检查的应用则能有效地克服这些不足,从而提高了检查的成功率与复查率。本文对近年来有关无痛纤维支气管镜检查的麻醉与管理的临床研究进展综述如下。     

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.     

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

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.