热休克蛋白70和血红素加氧酶-1表达在肾缺血后处理减轻肾缺血再灌注损伤中的作用

目的 评价热休克蛋白70(HSP70)和血红素加氧酶-1(HO-1)表达在肾缺血后处理减轻肾缺血再灌注损伤中的作用.方法健康雄性SD大鼠140只,体重250～280 g,采用随机数字表法,将大鼠随机分为4组(n=35):假手术组(S组)仅开腹,游离双侧肾脏,分离双侧肾蒂不夹团;肾缺血再灌注组(I/R组)夹闭双侧肾蒂缺血45 min,恢复灌注;缺血后处理组(IPo组)夹闭双侧肾蒂45 min,再灌注10 s,缺血10 s,反复3次,恢复灌注;HSP抑制剂槲皮黄酮+缺血后处理组(Q+IPo组)缺血前1 h 腹腔注射槲皮黄酮100 mg/kg,余操作同IPo组.于再灌注即刻(T0)、1、3、6、12、24、48 h(T1～6)时各组随机取5只大鼠抽心脏血后取肾,检测肾组织HSP70、HO-1的mRNA和蛋白表达,T3时抽心脏血,测定血清肌酐(Cr)和尿素氮(BUN)浓度、caspase-3 mRNA的表达,TUNNEL法检测肾组织凋亡细胞,计算凋亡指数(AI),光镜下观察肾组织病理学结果.结果 与S组比较,其余组T3时血清Cr和BUN浓度和AJ升高,caspase-3 mRNA表达上调,各时点HSF70、BO-1的mRNA和蛋白表达上调(P＜0.05);与I/R组比较,IPo组T3时血清Cr和BUN浓度和AI降低,caspase-3 mRNA表达下调,T1～5时HSP70、HO-1的mRNA和蛋白表达上调(P＜0.05);与IPo组比较,Q+IPo组T3时血清Cr和BUN浓度和AJ升高,caspase-3mRNA表达上调,T1～5时HSP70、HO-1的mRNA和蛋白表达下调(P＜0.05).IPo组肾组织病理学损伤较I/R组减轻,Q+IPo组肾组织病理学损伤程度与I/R组相似.结论 HSP70和H0-1表达参与了肾缺血后处理减轻肾缺血再灌注损伤的过程.

Abstract：

Objective To evaluate the role of the expression of heat shock protein 70 (HSP70) and heme oxygenase-1 (HO-1) in the reduction of renal ischemia-reperfusion (I/R) injury by ischemic postconditioning in tats.Methods One hundred and forty healthy male SD rats weighing 250-280 g were randomized into 4 groups ( n = 35 each) : sham operation group (S group) ; I/R group; ischemic postconditioning group (IPo group); quercetin (an inhibitor of HSP) + ischemic postconditioning group (Q + IPo group). Renal I/R was produced by clamping bilateral renal pedicels for 45 min followed by reperfusion. In group S, bilateral kidneys were only exposed through a midline incision but their- pedicels were not clamped. In IPo and Q + IPo groups, 45 min ischemia was followed by three 10 s episodes of ischemia at 10 s intervals for reperfusion and in addition intraperitoneal quercetin 100 mg/kg was injected at 1 h before ischemia in group Q + IPo. Blood samples from hearts were obtained at 0, 1, 3, 6, 12, 24 and 48 h of reperfusion (T0-6) and the rats were then sacrificed and kidneys removed to detect the expression of HSP70 and HO-1 mRNA and protein in renal tissues. The blood samples obtained at T3 were used to determine serum creatinine (Cr) and urea nitrogen (BUN) concentrations and the expression of caspase-3 mRNA . The apoptosis in the renal tissues was detected using TUNEL and apoptotic index ( AI) was calculated. Microscopic examination was performed with light microscope. Results Compared with group S, the serum Cr and BUN concentrations and AI were significantly increased at T3,the expression of caspase-3 mRNA was up-regulated at T3, and the expression of HSP70 and HO-1 mRNA and protein was up-regulated at T0-6 in the other groups (P ＜ 0.05) . Compared with group I/R, the serum Cr and BUN concentrations and AI were significantly decreased at T3, the expression of caspase-3 mRNA was down-regulated at T3, and the expression of HSP70 and HO-1 mRNA and protein was up-regulated at T1-5 in group IPo ( P ＜ 0.05) . Compared with group IPo, the serum Cr and BUN concentrations and AI were significantly increased at T3, the expression of caspase-3 mRNA was up-regulated at T3, and the expression of HSP70 and HO-1 mRNA and protein was down-regulated at T1-5, in group Q + IPo ( P ＜ 0.05) . The microscopic examination showed that the renal I/R injury was significantly attenuated by ischemic postconditioning and the degree of injury in group IPo was similar to that in group I/R. Conclusion The expression of HSP70 and HO-1 is involved in the reduction of renal I/R injury by ischemic postconditioning in rats.     

PI3K-Akt信号通路在七氟醚预处理减轻大鼠离体心脏缺血再灌注损伤中的作用

目的 评价磷脂酰肌醇-3-激酶-丝氨酸/苏氨酸激酶(PI3K-Akt)信号通路在七氟醚预处理减轻大鼠离体心脏缺血再灌注损伤中的作用.方法 健康成年雄性SD大鼠96只,体重220～280g,采用随机数字表法,将其随机分为6组(n=16):假手术组(S组)、缺血再灌注组(I/R组)、七氟醚预处理组(SP组)、渥曼青霉素组(W组)、二甲基亚砜组(D组)和七氟醚预处理+渥曼青霉素组(SW组).采用Langendorff装置建立大鼠离体心脏缺血再灌注模型.S组继续灌注180 min;I/R组平衡灌注30 min,缺血30 min,恢复灌注120 min;其余各组先平衡灌注15 min,SP组、W组、DMSO组和SW组分别用含2.4%七氟醚、100 nmol/L渥曼青霉察、20 μmol/L二甲基亚砜、2.4%七氟醚和100 nmol/L渥曼青霉素的K-H液灌注10 min,然后洗脱5 min,缺血30 min,恢复灌注120 min.各组随机取8个心脏,于平衡灌注末和再灌注15 min时,记录HR、左室舒张末压(LVEDP)、左室发展压(LVDP)、左心室内压最大上升速率(+dp/dtmax)和左心室内压最大下降速率(-dp/dtmax).再灌注15 min时取心肌组织,采用TUNEL法检测细胞凋亡,计算凋亡指数;采用Western blot法测定磷酸化Akt(p-Akt)表达.再灌注120 min时,取8个心脏,采用TIC染色法测定心肌梗死体积.结果 与S组比较,其余各组HR、LVDP和±dp/dtmax降低,LVEDP升高,I/R组、SP组和D组心肌p-Akt表达上调(P＜0.05);与I/R组比较,SP组LVDP和±dp/dtmax升高,LVEDP和凋亡指数降低,心肌p-Akt表达上调,心肌梗死体积减小(P＜0.05),SW组上述指标差异无统计学意义(P＞0.05).结论 七氟醚预处理可通过激活PI3K-Akt信号通路减轻大鼠离体心脏缺血再灌注损伤.

Abstract：

Objective To investigate the role of phosphatidyl-inositol 3-kinase-Akt (PI3k-Akt) signal pathway in the attenuation of ischemia-reperfusion (I/R) injury by sevoflurane preconditioning in isolated rat hearts. Methods Ninety-six adult male SD rats weighing 220-280 g were randomly divided into 6 groups ( n = 16 each): sham operation group (group S); I/R group; sevoflurane preconditioning group (group SP); wortmannin group (group W); dimethyl sulfoxide (DMSO) group (group D) and sevoflurane preconditioning + wortmannin group (group SW) . Their hearts were excised and perfused in a Langendorff apparatus with K-H solution saturated with 95%O2-5%C02 at 37 ℃ . The hearts were continuously perfused for 180 min in group S. After 15 min of equilibration, the isolated hearts were subjected to 30 min of ischemia followed by 120 min of reperfusion in SP, W, D and SW groups. Croups SP, W, D and SW received 10 min of perfusion with K-H solution containing 2. 4% sevoflurane, 100 nmol/L wortmannin, 20 μmol/L DMSO, and 2.4% sevoflurane + 100 nmol/L wortmannin, respectively, followed by 5 min washout before I/R. Eight hearts in each group were selected and HR, left ventricular end-diabetic pressure (LVEDP), left ventricular developed pressure (LVDP), and ± dp/dtmax were recorded at the end of equilibration and at 15 min of reperfusion, Myocardial tissues were obtained at 15 min of reperfusion for determination of apoptosis (by TUNEL) and phosphorylated Akt (p-Akt) expression (by Western blot) . Another 8 hearts were selected at 120 min of reperfusion for determination of myocardial infarct size by TTC staining. Result Compared with group S, LVDP and ± dp/dt,^ were significantly decreased and LVEDP was significantly increased in groups I/R, SP, W, D and SW, and myocardial p-Akt expression was up-regulated in groups I/R, SP and D ( P ＜ 0.05). Compared with group I/R, LVDP and ± dp/dtmax were significantly increased, LVEDP and apoptosis index were significantly decreased, myocardial p-Akt expression was up-regulated, and myocardial infarct size was significantly reduced in group SP (P ＜0.05) . Conclusion Activation of PI3K-Akt signal pathway is involved in the attenuation of I/R injury by sevoflurane reconditioning in isolated rat hearts.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

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.     

一氧化氮在七氟醚预处理减轻兔心肌缺血再灌注损伤中的作用

目的 评价一氧化氮在七氟醚预处理减轻兔心肌缺血再灌注损伤中的作用.方法 健康雄性新西兰大白兔40只,体重2.1～2.9 kg,随机分为5组(n=8):缺血再灌注组(IR组)、七氟醚预处理组(SEV组)、L-NAME组、七氟醚预处理+L-NAME组(SL组)和L-NAME+七氟醚预处理组(LS组).采用结扎冠状动脉前降支45 min,再灌注3 h的方法制备兔心肌缺血再灌注模型.SEV组吸入1.7%七氟醚30 min,洗脱15 min行预处理后制备模型;L-NAME组静脉注射一氧化氮合酶(NOS)抑制剂L-NAME 1 mg/kg,5 min后制备模型;SL组七氟醚预处理后,静脉注射L-NAME 1 mg/kg,5 min后制备模型;LS组静脉注射L-NAME 1 mg/kg,5 min后行七氟醚顶处理,制备模型.于模型制备前即刻(T0)、心肌缺血45 min(T1)、再灌注60 min(T2)、120 min(T3)、180 min(T4)时记录HR、MAP、左室收缩压(LVSP)和左室收缩压最大上升速率(+dp/dtmax),于T4时抽取股动脉血3 ml,测定血浆心肌肌钙蛋白T(cTnT)浓度、心肌磷酸肌酸激酶(CK-MB)和乳酸脱氢酶(LDH)活性,取心室肌组织,测定心肌缺血危险区(AAR)和梗塞区(IS)面积,并计算IS/AAR.结果 与IR组比较,SEV组缺血再灌注时+dp/dtmax升高,血浆cTnT浓度、CK-MB和LDH活性和心室肌IS/AAR降低(P<0.05),其余组上述指标差异均无统计学意义(P0.05).结论 一氧化氮参与了七氟醚预处理减轻兔心肌缺血再灌注损伤,一氧化氮可能是其保护作用中某一通路上的信号分子.     

不同浓度硝酸甘油对大鼠离体心脏缺血再灌注损伤的影响

目的 探讨不同浓度硝酸甘油对大鼠离体心脏缺血再灌注损伤的影响.方法 健康成年雌性SD大鼠,体重220～330 g,周龄7周,建立Langendorff离体心脏灌注模型,取模型制备成功的心脏30个,随机分为3组(n=10):缺血再灌注组(IR组)K-H液灌注15 min,停灌20 min,再灌注60 min;低浓度硝酸甘油组(LN组)采用含有2.5 μg/L硝酸甘油的K-H液灌注15 min,停灌20 min,再灌注60 min;高浓度硝酸甘油组(HN组)采用含有25μg/L硝酸甘油的K-H液灌注15 min,停灌20 min,再灌注60 min.于再灌注10、20、30、40、50、60 min时记录心率(HR)、冠状动脉流量(CF)、左心室舒张末压(LVEDP)、左心室发展压(LVDP)、左心室内压最大上升速率(+dp/dtmax)和左心室内压最大下降速率(-dp/dt_(max)).于平衡灌注末、再灌注5、30和60 min时收集冠状动脉流出液1.5 ml,测定乳酸脱氢酶(LDH)和肌酸激酶(CK)的活性;于再灌注60 min时取心脏,测定心肌梗死面积,计数心肌凋亡细胞.结果 与IR组比较,LN组HR、CF、LVDP,+dp/dt_(max)和-dp/dt_(max)升高,LVEDP、CK活性、LDH活性、心肌梗死面积和细胞凋亡率降低(P<0.05),HN组HR、CF、LVDP、+dp/dt_(max)和-dp/dt_(max)降低,LVEDP、CK活性、LDH活性、心肌梗死面积和细胞凋亡率升高(P<0.05).与LN组比较,HN组HR、CF、LVDP、+dp/dt_(max)和-dp/dt_(max)降低,LVEDP、CK活性、LDH活性、心肌梗死面积和细胞凋亡率升高(P<0.05).结论 低浓度硝酸甘油(2.5μg/L)可减轻大鼠离体心脏缺血再灌注损伤,而高浓度硝酸甘油(25 μg/L)则可加重心脏缺血再灌注损伤.     

线粒体ATP敏感性钾通道在利多卡因预先给药减轻大鼠离体心脏缺血再灌注损伤中的作用

目的 评价线粒体ATP敏感性钾通道在利多卡因预先给药减轻大鼠离体心脏缺血再灌注损伤中的作用.方法 雌性成年Wistar大鼠,体重220～250 g,采用Langendorff装置建立大鼠离体心脏缺血再灌注模型.取模型制备成功的大鼠心脏24个,随机分为3组(n=8):缺血再灌注组(IR组)、利多卡因组(L组)和利多卡因+格列苯脲组(LG组).K-H液平衡灌注10 min后,C组、L组和LG组分别灌注K-H液、含2.5 mg/L利多卡因的K-H液、含2.5 mg/L利多卡因+10μmol/L格列苯脲(线粒体ATP敏感性钾通道阻断剂)的K-H液20 min,然后缺血30 min,再灌注60 min.分别于平衡灌注末(T0)、再灌注15 min(T1)、30 min(T2)、45 min(T3)和60 min(T4)时,记录HR、左心室发展压(LVDP)、左心室内压最大上升速率(+dp/dtmax)和左心室内压最大下降速率(-dp/dtmax).于T0和T4时,收集冠状动脉流出液,测定乳酸脱氢酶(LDH)和肌酸激酶(CK)的活性.于T4时取心尖周围心肌组织,测定Na+-K+-ATP酶和SOD的活性、MDA和Ca2+的含量.结果 与IR组比较,L组HR、LVDP、+dp/dtmax和-dp/dtmax升高,CK和LDH的活性降低,心肌Na+-K+-ATP酶和SOD的活性升高,Ca2+和MDA的含量降低(P＜0.05),LG组上述各指标差异无统计学意义(P＞0.05).与L组比较,LG组HR、LVDP、+dp/dtmax和-dp/dmax.降低,CK和LDH的活性升高,心肌Na+-K+-ATP酶和SOD的活性降低,Ca2+和MDA的含量升高(P＜0.05).结论 利多卡因预先给药减轻大鼠离体心脏缺血再灌注损伤与促进线粒体ATP敏感性钾通道的开放有关.     

星状神经节阻滞对心肌缺血再灌注损伤的影响

目的：探讨左侧星状神经节阻滞对心肌缺血再灌注损伤的预防作用及其机制，以建立一种新的围术期心肌保护方法。方法：选用健康新西兰白兔32只，随机分为4组，A组为对照组，其他3组为缺血再灌注组，其中B组采用左侧星状神经节阻滞。常规建立在体心肌缺血再灌注损伤模型。分别于开胸后10min，阻断左前降支（LAD）前，再灌注5、30、90min测心率（HR）、左室峰压（LVP）、左室内压最大上升速率（ dp/dtmax），并经冠状静脉窦口抽血测神经肽Y(NPY）和去甲肾上腺素（NE）。结果：左侧星状神经节阻滞组，在心肌缺血再灌注5、30、90min时间点，冠状静脉血血浆NPY和NE水平均明显降低；在再灌注90min时，血流动力学指标LVP、 dp/dtmax值明显上升。结论：左侧星状神经节阻滞对心肌缺血再灌注损伤有一定预防作用。     

心肌细胞缝隙连接蛋白43在线粒体敏感性钾通道介导七氟醚预处理减轻大鼠离体心脏缺血再灌注中的作用

目的 评价心肌细胞缝隙连接蛋白43(Cx43)在线粒体敏感性钾(mito-KATP)通道介导七氟醚预处理减轻大鼠离体心脏缺血再灌注中的作用.方法 健康成年雄性SD大鼠40只,体重200～250 g,采用Langendorff灌注模型进行离体心脏灌注.采用随机数字表法,将心脏随机分为5组(n=8):对照组(C组)、缺血再灌注组(I/R组)、七氟醚预处理组(S组)、七氟醚预处理+5-羟葵酸(5-HD)组(SH组)和5-HD组(H组).采用结扎左冠状动脉前降支(LAD) 30 min,恢复灌注120 min的方法制备心脏缺血再灌注模型.各组平衡灌注10 min;然后C组持续灌注,仅于LAD下穿线而不结扎;I/R组继续灌注30 min后结扎LAD;S组、S+H组和H组结扎LAD前30 min时分别用3％七氟醚预先饱和的K-H液、3％七氟醚预先饱和的K-H液+100 μmol/L 5-HD和K-H液+100 μmol/L 5-HD灌注15 min,然后用K-H液冲洗15 min.分别于给药前(T0)、给药结束即刻(T1)、缺血前即刻(T2)、缺血30 min(T3)和再灌注120 min(T4)时,记录HR、左心室收缩压(LVSP)、左心室舒张压(LVDP)、左心室最大上升速率(+dp/dtmax)和左心室最大下降速率(- dp/dtmax).再灌注结束后,取左心室心肌组织,测定心肌梗死体积,采用免疫组化法测定心肌细胞Cx43表达,采用Western Blot法测定心肌细胞Cx43和磷酸化Cx43(p-Cx43)表达.结果 与C组比较,I/R组、S+H组和H组HR、LVSP、+dp/dtmax和- dp/dtmax降低,LVDP升高,心肌细胞Cx43和p-Cx43表达下调(P＜0.05).与I/R组比较,S组HR、LVSP、+dp/dtmax和- dp/dtmax升高,LVDP和心肌梗死体积降低,心肌细胞Cx43和p-Cx43表达上调(P＜0.05),S+H组和H组各指标差异无统计学意义(P＞0.05).结论 七氟醚预处理可能通过开放mito-KATP通道,促进心肌细胞Cx43磷酸化,减轻大鼠离体心脏缺血再灌注损伤.     

吡那地尔超极化停搏对大鼠离体心脏缺血再灌注时p38MAPK表达的影响

目的 评价吡那地尔超极化停搏对大鼠离体心脏缺血再灌注时p38丝裂原活化蛋白激酶(p38MAPK)表达的影响.方法 成年雄性SD大鼠48只,体重250～300 g,采用随机数字表法,将大鼠随机分为6组(n=8):自然停搏组(A组)、St.Thomas组(B组)、吡那地尔超极化停搏组(C组)、5-羟葵酸(5-HD)组(D组)、HMR-1098组(E组)和5-HD+HMR-1098组(F组).采用Langendorff离体心脏灌注模型,K-H液平衡灌注15 min后,A组阻断主动脉,不予停搏液灌注,使其自然停搏;B组灌注St.Thomas停搏液;C组灌注吡那地尔超极化停搏液;D组、E组和F组K-H液平衡灌注10 min后,分别灌注含5-HD、HMR-1098、5-HD+ HMR-1098的K-H液5min,再灌注吡那地尔超级化停搏液.心脏停跳缺血60 min后,K-H液再灌注30 min.于平衡灌注15 min和再灌注20 min时记录冠脉流量(CF)、心率(HR)、左室发展压(LVDP)、左室收缩压(LVSP)和左室压力瞬时最大变化率(dp/dtmax);于再灌注30 min时取心肌组织,采用Western blot法测定心肌磷酸化p38MAPK和非磷酸化p38MAPK的表达.结果 与C组相比,A组、B组、D组、E组和F组再灌注20min时CF、HR、LVSP、LVDP及dp/dt/dymax降低,再灌注30 min时磷酸化p38MAPK表达下调,非磷酸化p38MAPK表达上调(P＜0.05);与E组相比,D组和F组再灌注20 min时CF、HR、LVSP、LVDP及dp/dtmax降低,再灌注30 min时磷酸化p38MAPK表达下调,非磷酸化p38MAPK表达上调(P＜0.05).结论 吡那地尔超极化停搏可改善大鼠离体缺血再灌注心脏功能,其机制与上调磷酸化p38MAPK表达,下调非磷酸化p38MAPK表达有关,而这种调控作用与线粒体ATP敏感性钾通道关系更密切.     

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.     

舒芬太尼后处理和七氟醚后处理对大鼠离体心脏缺血再灌注损伤的影响

目的 评价舒芬太尼后处理和七氟醚后处理对大鼠离体心脏缺血再灌注损伤的影响.方法 雄性SD大鼠,体重230～250 g,成功制备Langendorff离体灌注模型的40个心脏随机分为4组(n=10):缺血再灌注组(Ⅰ组)、七氟醚后处理组(Ⅱ组)、舒芬太尼后处理组(Ⅲ组)和七氟醚联合舒芬太尼后处理组(Ⅳ组).采用K-H液平衡灌注(灌注压10 kPa)30 min,全心缺血40 min再灌注120 min.再灌注即刻时Ⅱ组、Ⅲ组和Ⅳ组进行药物后处理15 min:Ⅱ组K-H液中通入3.0%七氟醚,Ⅲ组K-H液中加入100 nmol/L舒芬太尼,Ⅳ组同时进行七氟醚后处理和舒芬太尼后处理.分别于平衡灌注末(基础状态)、再灌注15 min、30 min、60 min、90 min、120 min时记录左室收缩压(LVSP)、左室舒张末压(LVEDP)、左室发展压(LVDP)、左室内压上升最大速率(+dp/dtmax)、左室内压下降最大速率(-dp/dtmax)、心率(HR)和灌脉流量(CF).再灌注5 min时,收集冠脉流出液,测定肌酸激酶(CK)和乳酸脱氢酶(LDH)的活性.再灌注120 min时取心肌组织,测定心肌梗死体积、Bcl-2和Bax的表达水平,并计算Bcl-2和Bax表达的比值(Bcl-2/Bax).结果 与Ⅰ组比较,Ⅱ组、Ⅲ组和Ⅳ组LVSP、LVDP、+dp/dtmax、-dp/dtmax和CF升高,LVEDP和LDH、CK的活性降低,心肌梗死体积缩小,Bcl-2表达上调,Bax表达下调,Bcl-2/Bax升高(P＜0.05或0.01);Ⅱ组、Ⅲ组和Ⅳ组间上述指标差异无统计学意义(P＞0.05).结论 舒芬太尼后处理可减轻大鼠心肌缺血再灌注损伤,联合七氟醚后处理时心肌保护作用并未增加,其心肌保护的机制与上调Bcl-2表达、下调Bax表达从而抑制细胞凋亡有关.