Role of tetrahydrobiopterin on ischemia-reperfusion injury in isolated perfused rat hearts

AIM: It has recently been shown that nitric oxide synthase in the presence of suboptimal levels of tetrahydrobiopterin (BH(4)), an essential cofactor of nitric oxide synthase, may favor increased production of oxygen free radicals. This study was designed to define the role of BH(4) in myocardial ischemia-reperfusion injury. METHODS: Isolated perfused rat hearts were subjected to 37 degrees C ischemia and reperfusion. Hearts were received with BH(4) or vehicle for 5 min just before ischemia and during the first 5 min of the reperfusion period. The effects of BH(4) on left ventricular function, myocardial contents of lipid peroxidation and high energy phosphates, and levels of lactate dehydrogenase and nitrite plus nitrate in perfusate before ischemia and after reperfusion were estimated. Moreover, the effect of BH(4) given with 2,4-diamino-6-hydroxypyrimidine (DAHP), a selective inhibitor of BH(4) production, intraperitoneally 24 h before the experiments were estimated. RESULTS: BH(4) improved contractile and metabolic abnormalities in reperfused hearts. Furthermore, BH(4) significantly alleviated ischemic contracture during ischemia, and restored diminished perfusate levels of nitrite plus nitrate after reperfusion. On the other hand, DAHP-treatment aggravated ischemia-reperfusion induced functional and metabolic abnormalities. Administration of BH(4) improved DAHP-induced functional and metabolic abnormalities. CONCLUSION: Results demonstrated that BH(4) lessens ischemia-reperfusion injury in isolated perfused rat hearts. Conversely, deficiency of BH(4) seems to accelerate endothelial dysfunction and myocardial ischemia-reperfusion injury. Present data may be compatible with the hypothesis that nitric oxide synthase in the presence of insufficiency of BH(4) serve as the cause of oxidative injury.     

槲皮素对缺血再灌注大鼠离体心脏的作用

目的 观察槲皮素(Quercetin)对缺血再灌注损伤(IRI)离体大鼠心脏的作用.方法 将32只SD大鼠随机分为4组:空白对照组(Control);给药对照组(Control+Que);缺血再灌注组(I/R);缺血再灌注给药组(I/R+Que),行Langendorff心脏灌注,给药组预防性给予槲皮素(5 μmol/L).监测各组心功能(±dp/dtmax),比较再灌注1 h心肌尼克酰胺腺嘌呤二核苷酸磷酸氧化酶(NOX2)、一氧化氮合酶(iNOS、eNOS)表达和超微结构的变化.结果 I/R组与Control组比较心功能显著降低(分别为18.91±3.38、-22.43±8.84和60.65±11.65、-56.62±8.49,P＜0.01),NOX2、iNOS、eNOS mRNA(分别为0.1590±0.0539、0.0897±0.0236、0.0154±0.0061和0.0247±0.0070、0.0377±0.0135、0.0091±0.0033,P＜0.05)和蛋白的表达均显著增加,心肌超微结构严重损伤;与I/R比较I/R+Que组(45.77±8.05,-42.10±8.71)显著增强心功能(P＜0.01),显著降低NOX2、iNOS、eNOS mRNA(分别为0.0864±0.0358、0.0445±0.0104、0.0085±0.0032,P＜0.05)和蛋白的表达,明显减轻心肌超微结构的损伤.结论 在离体水平预防性给予槲皮素能够显著减轻缺血再灌注对大鼠心肌造成的损伤,保护心脏.

Abstract：

Objective To observe the effect of quercetin (Que) on isolated rat hearts after ischemia-reperfusion injury (IRI). Methods Thirty-two SD rats were divided randomly into 4 groups with 8 in each group: ( 1 ) Control group, isolated hearts contiuosly peffused without ischemia; (2) Control + Que group: isolated hearts contiuosly perfused without ischemia but the adminstration of Que (5 μmol/L) 5 min after perfusion; (3) I/R group: isolated hearts perfused with 30 min global ischemia followed by reperfusion; (4) I/R + Que group: isolated hearts perfused with 30 min global ischemia followed by reperfusion and the adminstration of Que (5 μmol/L) 10 min before ischemia. Hemodynamic parameters ( ± dp/dtmax),myocardial ultrastructure, nicotinamide adenine dinucleotide phosphate (NADPH) oxidases 2 ( NOX2),inducible nitric oxide synthase (iNOS) and endothelial nitric oxide synthase (eNOS) mRNA and protein expression after reperfusion were compared among the four groups. Results As compared with control group, hemodynamic parameters were greatly decreased after reperfusion ( 18.91 ± 3. 38, - 22. 43 ± 8. 84vs 60. 65 ± 11.65, - 56. 62 ± 8. 49 ,P ＜ 0. 01 ), myocardial ultrastructures were significantly destroyed and the expression levels of NOX2, iNOS, eNOS mRNA and protein were significantly increased after 60-min reperfusion (0. 1590 ±0.0539, 0.0897 ±0.0236, 0.0154 ±0.0061 vs 0.0247 ±0.0070, 0.0377 ±0. 0135, 0. 0091 ± 0. 0033, P ＜ 0. 05 ) in I/R group. As compared with I/R group, hemodynamic parameters were significantly recovered (45.77 ± 8.05, - 42. 10 ± 8. 71, P ＜ 0. 01 ), myocardial ultrastructures were well protected and the expression levels of NOX2, iNOS, eNOS were significantly decreased (0. 0864± 0. 0358, 0. 0445 ± 0. 0104, 0. 0085 ± 0. 0032, P ＜ 0. 05 ) in I/R + Que group, but there was no significant difference between control group and control + Que group ( P ＞ 0. 05 ). Conclusion Que can protect isolated perfused rat hearts from IRI by its antioxidative effect.     

异氟烷预处理对大鼠离体心脏缺血再灌注损伤的保护作用

目的探讨异氟烷预处理对大鼠离体心脏缺血再灌注损伤的保护作用。方法50只SD大鼠随机分为5组：对照组（C组）、缺血再灌注组（Ⅰ组）、0．5％、1．0％、2．0％异氟烷预处理组（P1、P2、P3组），每组10只。采用Langendorff离体心脏灌注模型，经主动脉用K-H液平衡灌注。除C组外，其余组均全心缺血30min再灌注60min。P1、P2、P3组在缺血前分别用含相应浓度异氟烷的KH液灌注15min，再用K-H液冲洗15min。记录平衡灌注末、缺血前即刻、再灌注30、60min时左室舒张末压（LVEDP）、左室收缩压（LVSP）、左室内压下降最大速率（dp／dtmin）、左室内压上升最大速率（dp，dtmax）、心率（HR）。再灌注60min时，计算心肌梗死面积百分比、线粒体和胞浆的细胞色素C水平。结果与C组比较，再灌注期间Ⅰ组LVEDP升高，LVSP、dp／dtmax、dp／dtmin降低，P1、P2、P3组LVEDP升高，I、P1组心肌梗死面积百分比升高，I、P1、P2组线粒体细胞色素C水平降低，胞浆细胞色素C水平增高；与Ⅰ组比较，P1、P2、P3组LVEDP及心肌梗死面积百分比降低，线粒体及胞浆细胞色素C水平增高，胞浆细胞色素C水平降低（P〈0．05或0．01）。P2组胞浆细胞色素C水平高于P1组；与P1、P2组比较，P3组线粒体细胞色素C水平增高，胞浆细胞色素C水平降低（P〈0．05）。结论通过抑制线粒体细胞色素C释放到胞浆。异氟烷预处理对大鼠离体心脏缺血再灌注损伤有一定的保护作用。     

Beneficial effect of tetrahydrobiopterin on the survival of rats exposed to hepatic ischemia-reperfusion injury

INTRODUCTION: The protective role of nitric oxide (NO) against hepatic ischemia-reperfusion (I/R) injury remains controversial. In this study we investigated the effect of tetrahydrobiopterin (BH4) on the survival of rats exposed to an hepatic I/R injury. METHODS: The rats were subjected to 100 minutes of 70% hepatic ischemia 30 minutes after administration of BH4 or saline. A specific inducible NO synthase (iNOS) blocker, 1400W, was used to evaluate endogenous iNOS. NOS protein measured the histological appearance of the liver by Western blotting, and survival was evaluated after reperfusion. RESULTS: The 1-week survival rate was 60% among the BH4 group and 10% for the saline group. The serum ALT and bilirubin values in the BH4 group were significantly lower than the saline group. Histological examination of the liver revealed only a small necrotic area in the BH4 group as opposed to massive necrosis and cell infiltration in the saline group. Injection of 1400W significantly decreased the prolongation of survival produced by BH4. CONCLUSIONS: BH4 significantly improved the survival rate, the histological findings, and the liver function, thereby reducing liver failure. Western blotting showed a higher level of iNOS protein in the BH4 group than the saline group, 1400W suppressed this effect of BH4. Taken together, these observations suggest that NO derived from reactions driven by BH4-induced iNOS exerts a protective effect against reperfusion injury.     

吗啡后处理对大鼠离体心脏缺血再灌注损伤的影响

目的 评价吗啡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180～200 g,应用Langendorff灌流装置,采用全心停灌45 min、再灌注60 min的方法制备大鼠离体心脏缺血再灌注模型.实验一:取模型制备成功的心脏32个,随机分为4组(n=8):Ⅰ组～Ⅳ组,Ⅰ组不予处理,Ⅱ组～Ⅳ组于再灌注即刻分别灌注含0.3、3.0和30 μmol/L吗啡的K-H液10 min,随后灌注正常K-H液50 min;实验二:根据实验一的结果,选择对离体心脏缺血再灌注损伤影响最强的吗啡浓度,另取模型制备成功的心脏32个,随机分为4组(n=8):Ⅰ组～Ⅳ组,Ⅰ组不予处理,Ⅱ组～Ⅳ组于再灌注即刻分别灌注含吗啡的K-H液5、10和20 min,随后灌注正常K-H液50 min;实验三:根据实验二的结果,选取对离体心脏缺血再灌注损伤影响最强的吗啡后处理方法.另取模型制备成功的心脏37个,随机分为5组:Ⅰ组(n=8)不予处理;Ⅱ组(n=8)、Ⅲ组～Ⅴ组(n=7)于再灌注即刻分别灌注含吗啡、10 μmol/L非选择性阿片受体阻断剂纳洛酮和吗啡、5 μmol/L选择性κ受体阻断剂nor-binahorphimine和吗啡、5 μmol/L选择性δ受体阻断剂naltrindole和吗啡的K-H液,各组均再灌注正常K-H液50 min.于再灌注60 min时测定心肌肌酸激酶同工酶(CK-MB)活性,计算心肌缺血危险区/梗塞区(IS/AAR).结果 根据实验一、二的结果于再灌注即刻灌注含3.0 μmol/L吗啡的K-H液10 min行后处理.实验三的结果:与Ⅰ组比较,Ⅱ组和Ⅴ组心肌IS/AAR和CK-MB活性降低,Ⅳ组心肌CK-MB活性降低(P<0.05或0.01),Ⅲ组以上指标差异无统计学意义(P>0.05);与Ⅱ组比较,Ⅲ组和Ⅳ组心肌IS/AAR和CK-MB活性升高(P<0.01),Ⅴ组上述指标差异无统计学意义(P>0.05).结论 吗啡后处理可减轻大鼠离体心脏缺血再灌注损伤,此作用可能与激活心肌κ受体有关.     

高渗灌注对大鼠心肌缺血-再灌注损伤的影响

目的在Langendorff灌注模型上研究高渗灌注对大鼠心肌缺血-再灌注损伤耐受性的影响。方法健康雄性SD大鼠20只,随机分为对照组(C组)和高渗氯化钠灌注组(H组),每组10只。腹腔注射戊巴比妥钠(60mg/kg)麻醉后快速取出心脏接上主动脉插管置于Langendorff装置上,Krebs-Henseleit缓冲液平衡逆行灌注20min。待HR及冠脉流量平稳后夹闭灌注道进行全心热缺血30min,复灌40min。通过多道生理记录仪持续监测HR、左心室压峰值(LVPSP)、左室舒张末压(LVEDP)和左室压力最大上升/下降速率(±dp/dtmax),计算左室发展压(LVDP=LVPSP-LVEDP),用左室发展压与心率乘积(RPP=LVDP×HR)表示左室做功。结果同C组比较,H组再灌注心功能恢复显著改善:HR[(89.5±7.8)%vs(57.9±4.6)%,P<0.05]、LVPSP[(83.5±7.8)%vs(62.9±4.1)%,P<0·05]、RPP[(66.3±9.4)%vs(36.4±3.8)%,P<0.05]、冠脉流量(CF)[(61.2±8.9)%vs(41.9±4.0)%,P<0.05]、+dp/dtmax[(60.4±6.9)%vs(22.9±3.4)%,P<0.01]和-dp/dtmax[(69.5±6.6)%vs(34.3±3.3)%,P<0.01];肌酸激酶(CK)释放量显著降低(P<0.05)。结论高渗灌注减轻心肌缺血-再灌注损伤。     

左旋卡尼汀对离体心肌缺血再灌注损伤的保护作用

目的探讨左旋卡尼汀增补于停搏液中对离体鼠心再灌注损伤的保护作用。方法将32只SD大鼠随机分为左旋卡尼汀3个剂量(2．5、5．0、10．0 mmol／L)组和对照组。离体鼠心在改良的Langendorff灌注模型上30 min预灌注,120 min缺血、60 min再灌注。缺血前及再灌注期间测定血流动力学指标、心肌超氧化物歧化酶(SOD)、丙二醛(MDA)含量和三磷酸腺苷(ATP)水平。电镜观察心肌超微结构。结果再灌注60 min后,左旋卡尼汀5 mmol／L剂量组和10 mmol／L剂量组与对照组相比,冠脉流量(CF)[(68．39±12．71)％、(72．27±6．27)％比(44．94±13．26)％]、左室收缩压(LVSP)[(73．04±3．32)％、(77．8±3．80)％比(62．29±4．14)％]、左室舒张末压(LVEDP)[(0．38±0．01)、(0．36±0．01)比(0．43±0．01)mmHg(1mmHg=0．133 kPa)]、左室压力变化速率(+dp／dt)[(69．66±0．92)％、(71．34±0．66)％比(62．16±1．21))％]、(-dp／dt) [(68．39±12．71)％、(72．27±6．27)％比(44．94±13．26)％],其差异均有统计学意义(P＜0．01)。心肌超微结构的改善,也优于对照组,尤其是10 mmol／L剂量组,2．5 ml／L组没有变化。左旋卡尼汀5 mmol／L剂量组和10 mmol／L剂量组丙二醛(MDA)含量显著低于对照组(19．04±0．41)、(17．60±0．53)nmol／mg蛋白比(27．36±1．23)nmol／mg蛋白,P＜0．01),超氧化物歧化酶(SOD) [(218．20±14．91)、(238．63±7．61)U／mg蛋白比(141．80±15．17)U／mg蛋白]含量和三磷酸腺苷(ATP)水平[(3．83±0．20)、(5．26±0．18)μmol／L比(1．36±0．08)μmol／L]显著高于对照组(P＜0．01)。结论左旋卡尼汀(5～10 mmol／L)增补于停搏液中可减轻心肌缺血再灌注损伤,具有良好的心肌保护作用并在一定范围内呈剂量依赖性,10mmol／L剂量组心肌保护效果最佳。     

右美托咪啶预处理对大鼠离体心脏缺血再灌注损伤的影响

目的 评价右美托咪啶预处理对大鼠离体心脏缺血再灌注损伤的影响.方法 健康清洁级雄性Wistar大鼠24只,体重230～ 260 g,制备离体Langendorff心脏灌注模型后,采用随机数字表法,将离体心脏随机分为3组(n=8):缺血再灌注组(I/R组)、右美托咪啶Ⅰ组(DI组)、右美托咪啶Ⅱ组(DⅡ组).各组均先用K-H液平衡灌注10 min后,I/R组用K-H液继续灌注30 min,D I组和DⅡ组分别用含有0.23.、2.30ng/ml右美托咪啶的K-H液继续灌注20 min,再用K-H液冲洗10 min.各组心脏均缺血30 min,K-H液再灌注120 min.于平衡灌注末、再灌注5、30、60和120min时收集冠脉流出液,测定肌酸激酶(CK)和乳酸脱氢酶(LDH)活性.再灌注末取心肌组织,测定SOD活性及MDA含量.结果 与I/R组比较DⅠ组和DⅡ组冠脉流出液CK、LDH活性、心肌组织MDA含量降低,心肌组织SOD活性升高(P＜0.05);与DI组比较,DⅡ组冠脉流出液CK、LDH活性、心肌组织MDA含量降低,心肌组织SOD活性升高(P＜0.05).结论 右美托咪啶预处理可减轻大鼠心肌缺血再灌注损伤,且与浓度有关.     

二氮嗪后处理对大鼠离体心脏缺血再灌注损伤的影响

目的 评价二氮嗪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250～300 g,成功建立Langendorff再灌注模型的64个心脏随机分为4组(n=16):正常对照组(C组)、缺血再灌注组(I/R组)、二氮嗪后处理组(D组)和线粒体ATP敏感性钾通道阻断剂5-羟葵酸+二氮嗪后处理组(5-HD+D组).采用K-H液平衡灌注20 min时,C组继续灌注K-H液70 min;I/R组、D组和5-HD+D组进行心肌缺血40 min,I/R组缺血前灌注4 ℃ ST.Thomas停跳液10 ml/kg;D组再灌注5 min时灌注含50μmol/L二氮嗪的K-H液5 min,然后再灌注20 min;5-HD+D组灌注二氮嗪前灌注含100 μmol/L 5-羟葵酸的K-H液5 min,再灌注20 min.分别于平衡灌注末与再灌注末时取8个心脏,记录心功能指标,然后提取线粒体,测定心肌细胞线粒体膜电位(MMP)、氧自由基(ROS)生成量和呼吸功能指标.结果 各组平衡灌注末时各指标差异无统计学意义(P＞0.05).与C组比较,再灌注末时其余3组心功能和线粒体呼吸功能减退,MMP降低,ROS生成量增加(P＜0.05或0.01);与I/R组和5-HD+D组比较,D组心功能和线粒体呼吸功能改善,MMP升高,ROS水平降低(P＜0.01).结论二氮嗪后处理可减轻大鼠心肌缺血再灌注损伤,其机制与开放线粒体ATP敏感性钾通道而改善线粒体功能有关.     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

目的 探讨吗啡预处理-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180～200 g,应用Langendorff体外灌流装置,采用全心停灌45 min、再灌注60 min的方法制备大鼠离体心脏缺血再灌注模型.取模型制备成功的心脏40个,随机分为5组(n=8):缺血再灌注组(IR组)、吗啡预处理组(M1组)、吗啡后处理组(M2组)、吗啡预处理-后处理组(M1+M2组)、5-羟葵酸(5-HD)混合吗啡后处理组(5-HD+M2组).M1组全心停灌前30 min灌注含3.0 μmol/L吗啡的K-H液20 min,随后灌注K-H液10 min.M2组再灌注即刻灌注含3.0 μmol/L吗啡的K-H液10 min,随后灌注正常K-H液50 min.5-HD+M1组再灌注即刻灌注含3.0 μmol/L吗啡+10-4nunol/L 5-HD的K-H液10 min,随后灌注正常K-H液50 min.于再灌注60 min时,测定心肌肌酸激酶(CK-MB)活性,计算心肌梗死区与缺血危险区的比值(IS/AAR).结果 与IR组相比,其余各组IS/AAR减少,CK-MB活性降低(P<0.05);与M2组比较,5-HD+M2组CK-MB活性及IS/AAR升高(P<0.05);M1组、M2组和M1+M2组上述指标比较差异无统计学意义(P>0.05).结论 吗啡预处理.后处理虽然可减轻大鼠离体心脏缺血冉灌注损伤,但是与单独应用时效果相似,其原因可能是两者单独应用减轻心脏缺血再灌注损伤的机制均与开放线粒体ATP敏感性钾通道有关.     

吗啡预处理-后处理对大鼠离体心脏缺血再灌注损伤的影响

Objective To evaluate the effects of morphine preconditioning-postconditioning on ischemia-reperfusion (I/R) injury in isolated rat hearts. Methods Male SD rats weighing 180-200 g were killed after intraperitoneal injection of heparin 500 U/kg. The hearts were immediately removed and perfused in a Langendorff apparatus with K-H solution gassed with 95%O2-5%CO2 .HR and left ventricular systolic pressure (LVSP) were measured from a fluid-filled latex balloon in the left ventricle. Global myocardial ischemia was induced by interrupting perfusion for 45 min followed by 60 min reperfusion. Forty isolated rat hearts were randomly divided into 5 groups (n = 8 each): group 1 (I/R); group II morphine preconditioning (M1 ); group Ⅲ morphine postconditioning (M2); group IV M1 + M2; group V 5-hydroxydecanoate (5-HD) + M2. Group M1 was perfused with K-H solution containing morphine 3.0 μmol/L for 20 min 30 min before ischemia followed by 10 min normal K-H solution perfusion. Group M2 was perfused with K-H solution containing morphine 3.0 μmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Group 5-HD + M2 was perfused with K-H solution containing morphine 3.0 μmol/L+ 5-HD 10-4 mmol/L for 10 min at the beginning of reperfusion followed by 50 min normal K-H solution perfusion. Myocardial CK-MB activity was measured and myocardial infarct size (IS/AAR) detennined (by 2,3,5-triphenyl tetrazolium staining) at the end of 60 min reperfusion. Results The preconditioning, postconditioning and combination of preconditioning and postconditioning with morphine 3.0 μmol/L perfusion for 10 min all provided cardio-protective effects in terms of IS/AAR and myocardial activation of CK-MB. Conclusion Although the combination of morphine preconditioning and postconditioning can protect the heart against I/R injury, the effects are similar to those of either of them alone, and the reason may be that either of them alone protects the heart against I/R injury via activating mitoKATP .