七氟醚预先给药对大鼠肾脏缺血再灌注时细胞凋亡的影响

目的 探讨七氟醚预先给药对大鼠肾脏缺血再灌注时细胞凋亡的影响.方法 健康清洁级雄性SD大鼠30只,体重220～260 g,采用随机数字表法,将大鼠随机分为3组(n=10):对照组(C组)、缺血再灌注组(I/R组)、七氟醚组(S组).I/R组和S组采用夹闭左肾蒂45 min后恢复再灌注的方法 建立肾脏缺血再灌注模型,C组腹部正中切口,右肾切除,左肾蒂游离后,缝合腹腔;S组模型制备前30 min开始吸入2.2%七氟醚和氧气的混合气体至再灌注3 h.于再灌注3 h时采集下腔静脉血样5 ml,测定血清尿素氮(BUN)、肌酐(Cr)浓度,然后取肾组织,光镜下观察肾组织病理学结果,TUNEL法检测细胞凋亡,计算细胞凋亡指数,采用RT-PCR和Western blot法测定血红素氧合酶-1(HO-1)mRNA及蛋白表达水平.结果 与C组比较,I/R组和S组血清BUN、Cr浓度、肾脏近曲小管坏死程度、细胞凋亡指数升高,HO-1 mRNA和蛋白表达上调(P＜0.05);与I/R组比较,S组血清BUN、Cr浓度、细胞凋亡指数、肾脏近曲小管坏死程度降低,HO-1 mRNA表达上调(P＜0.05).结论 七氟醚预先给药可通过抑制细胞凋亡而减轻大鼠肾脏缺血再灌注损伤,其抑制细胞凋亡作用可能与HO-1 mRNA表达上调有关.

Abstract：

Objective To investigate the effects of sevoflurane pretreatment on renal ischemia-reperfusion (I/R)-induced apoptosis in kidney in rats. Methods Thirty pathogen-free male SD rats weighing 220-260 g were randomized into 3 groups (n=10 each):group control (group C);group I/R and group sevoflurane(group S). Renal I/R was induced by clamping the left renal pedicle for 45 min in I/R and S groups. In group S inhalation of 2.2% sevoflurane in O2 was started at 30 min before operation and maintained throughout the experiment.Venous blood samples were taken at 3 h of reperfusion for determination of serum BUN and Cr concentrations. The animals were then sacrificed and the left kidneys were removed for microscopic examination, detection of apoptosis(by TUNEL)and determination of heme oxygenase-1(HO-1) mRNA and protein expression (by RT-PCR and Western blot).Results Renal I/R significantly increased serum BUN and Cr concentrations, apoptotic index(percentage of apoptotic cells) and the severity of necrosis of renal proximal convoluted tubules (0=normal,4=necrosis of whole segment of proximal convoluted tubules).Sevoflurane inhalation attenuated the I/R-induced changes mentioned above.HO-1 mRNA and protein expression was up-regulated by I/R and HO-1 mRNA expression was further up-regulated by sevoflurane inhalation.Conclusion Sevoflurane pretreatment can protect kidney against I/R injury by attenuating cell apoptosis.Up-regulation of HO-1 mRNA expression may be involved in the mechanism.     

肾缺血后处理对热休克蛋白表达的影响及作用

目的 评价肾缺血后处理(ischemic postconditioning,IPo)对热休克蛋白(heat shock protein,HSP)70、HSP27和血红素加氧酶-1(heme oxygenase-1,HO-1,即HSP32)表达的影响及在减轻肾缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)中的作用.方法 健康雄性SD大鼠140只,体重250 g～280 g,采用随机数字表法随机分为4组(每组35只):假手术组(S组)仅开腹,游离双侧肾脏,分离双侧肾蒂不夹闭;缺血/再灌注(ischemia/reperfusion,I/R)组,夹闭双侧肾蒂缺血45 min,恢复灌注;IPo组,夹闭双侧肾蒂45 min,再灌注10 s,缺血10s,反复3次,恢复灌注;HSP抑制剂槲皮黄酮+IPo组(Q+IPo组),缺血前lh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)时取5只大鼠经心脏抽血后迅速处死取肾,采用逆转录-多聚酶链反应(RT-PCR)和免疫组织化学法分别检测各时点肾组织HSP70、HSP27和HO-1的mRNA和蛋白表达,测定T3时血清肌酐(creatinine,Cr)和尿素氮(urea nitrogen,BUN)浓度、肾组织丙二醛(methylene dioxyamphetamine,MDA)含量和超氧化物歧化酶(superoxide dismutase,SOD)活性、肾组织核因子-κB(nuclear factor-kappa B,NF-κB)表达和血清肿瘤坏死因子-α(tumor necrosis factorα,TNF-α)浓度,光镜下观察肾组织病理学结果. 结果 S组HSP70、HSP27和HO-1的mRNA有微量表达,蛋白几乎无表达,其余组在To时开始表达,逐渐升高,T3时达高峰,随后逐渐下降.与S组比较,其余组各时点HSP70、HSP27和HO-1的mRNA和蛋白表达上调(P＜0.05),IPo组较I/R组T2～5时HSP70、HSP27和HO-1的mRNA和蛋白表达上调(P＜0.05),Q+IPo组较IPo组T2～5时HSP70、HSP27和HO-1的mRNA和蛋白表达下调(P＜0.05).T3时血清Cr、BUN和TNF-α浓度I/R组分别为(102±5) μmol/L、(25.7±3.9) mmol/L、(2.29±0.18) μg/L,IPo组分别为(64±5)μmol/L、(11.3±3.0) mmol/L、(1.76±0.13)μg/L,Q+IPo组分别为(101±6)μmol/L、(26.5±4.5) mmol/L、(2.31±0.17) μg/L,均高于S组(46±6) μmol/L、(5.1±1.9) mmol/L和(1.13±0.14) μg/L(P＜0.05),IPo组三者浓度较I/R组降低(P＜0.05),Q+IPo组较IPo组升高(P＜0.05).T3时MDA含量I/R组(2.20±0.23) nmol/mgprot、IPo组(1.35±0.13) nmol/mgprot和Q+IPo组(2.25±0.16) nmol/mgprot较S组(1.02±0.19) nmol/mgprot升高(P＜0.05),SOD活性I/R组(104±6) U/mgprot、IPo组(124±4) U/mgprot和Q+IPo组(106±5) U/mgprot较S组(147±6) U/mgprot 降低(P＜0.05),IPo组与I/R组比较MDA含量降低和SOD活性升高(P＜0.05),Q+Ipo组与IPo组比较MDA含量升高和SOD活性降低(P＜0.05),肾组织NF-κB表达I/R组、IPo组和Q+IPo组较S组增高,IPo组较I/R组表达降低,Q+IPo组较IPo组表达增高(P＜0.05).I/R组与Q+Ipo组相比,各指标差异无统计学意义(P＞0.05).与S组比较,其余3组有程度不等的肾组织病理学损伤,IPo组损伤较I/R组减轻,Q+IPo组损伤程度与I/R组相似. 结论 IPo上调了HSP70、HSP27和HO-1的表达;HSP高表达参与了肾IPo减轻肾I/RI的过程.     

七氟醚预处理对大鼠肾缺血再灌注损伤的影响

目的 评价七氟醚预处理对大鼠肾缺血再灌注损伤的影响.方法 雄性SD大鼠24只,体重250～300 g,采用随机数字表法,将大鼠随机分为3组(n=8):假手术组(S组)、肾缺血再灌注组(I/R组)和七氟醚预处理组(SP组).I/R组和SP组采用切除右肾然后夹闭左侧肾动脉45 min再开放的方法 制备肾缺血再灌注模型.SP组吸入2.2%七氟醚1 h,停止吸入后10 min时进行肾缺血.于再灌注2 h时采集静脉血样,测定血清肌酐(Cr)、尿素氮(BUN)和胱抑素C(Cys C)的浓度,取肾组织,光镜下及透射电镜下观察病理学结果,并根据肾小管病变程度进行Paller评分.结果 与S组比较,I/R组血清Cr和BUN浓度差异无统计学意义(P＞0.05),血清Cys C浓度和Paller评分明显升高(P＜0.05);与I/R组比较,SP组血清Cys C浓度和Paller评分明显降低(P＜0.05).SP组肾组织损伤程度轻于I/R组.结论 七氟醚预处理可减轻大鼠肾缺血再灌注损伤.

Abstract：

Objective To investigate the effects of sevoflurane preconditioning on renal ischemia-reperfusion(I/R)injury in rats.Methods Twenty-four adult male SD rats weighing 250-300 g were randomly divided into 3 groups(n=8 each):sham operation group (group S);I/R group; sevoflurane preconditioning group (group SP). After the rats underwent right nephrectomy, renal I/R was produced by occlusion of left renal artery for 45 min followed by reperfusion in I/R and SP groups.In group SP, the rats inhaled 2.2% sevoflurane for 1 h, then the inhalation was stopped and renal ischemia was performed 10 min later. Venous blood samples were collected at 2 h of reperfusion to determine the concentrations of serum creatinine(Cr), urea nitrogen (BUN), cystatin C (Cys C) . The renal tissues were obtained for microscopic examination, and Paller's score was recorded. Results Compared with group S, there was no significant difference in the serum Cr and BUN concentrations (P＞0.05), while the serum Cys C concentration and Paller's score for acute renal tubular injury were significantly increased in group I/R(P＜0.05). The serum Cys C concentration and Paller's score were significantly lower in group SP than in group I/R(P＜0.05).I/R-induced renal injury was significantly reduced in group SP compared with group I/R. Conclusion Preconditioning with sevoflurane can provide significant protection against renal I/R injury.     

不同剂量左旋甲状腺素钠预处理对幼龄大鼠心肌缺血再灌注损伤的影响

目的 评价不同剂量左旋甲状腺素钠预处理对幼龄大鼠心肌缺血再灌注损伤的影响.方法 健康雌性 Wistar大鼠48只,日龄35 d,体重120～140 g,采用随机数字表法,将其随机分为6组(n=8):对照组(C组)、缺血再灌注组(I/R组)和不同剂量左旋甲状腺素钠预处理组(LS1-4组).C组和I/R组大鼠采用普通饲料喂养7 d;LS1-4组大鼠除了采用普通饲料喂养之外,每天胃内灌注左旋甲状腺素钠10、20、40和80 μg/100 g.第8天时,抽取外周静脉血样,测定血清甲状腺激素水平.采用Langendorff装置建立大鼠离体心脏缺血再灌注模型.C组K-H液持续灌注80 min;其余各组K-H液平衡灌注30 min,然后全心缺血20 min,恢复灌注30 min.于平衡灌注20 min和再灌注30 min时,记录HR、SP、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),计算再灌注30min时HR、SP、+dp/dtmax和-dp/dtmax的恢复率.于平衡灌注10 min和再灌注15 min时,收集冠状动脉流出液2 ml,测定CK-MB的活性.再灌注30 min时,取心室肌组织,采用Western blot法检测心肌热休克蛋白70(HSPT0)的表达,采用RT-PCR法测定甲状腺激素受体(TR)亚型(TRα1、TRα2和TRβ1)mRNA以及肌球蛋白重链α和β(MHCα和MHCβ)mRNA的表达.结果 与C组相比,I/R组HR、SP和±dp/dtmax的恢复率降低,冠脉流出液CK-MB活性升高,心肌MHCα mRNA表达下调,LS1-4组SP和±dp/dtmax的恢复率降低,冠脉流出液CK-MB活性升高,心肌HSP70和MHCα mRNA表达上调,LS2-4组血清甲状腺激素水平升高,心肌TRα1 mRNA表达上调(P＜0.05).与I/R组相比,LS1-4组HR和±dp/dtmax的恢复率升高,心肌HSP70表达上调,MHCa mRNA表达上调,MHCβ mRNA表达下调,LS1-3组冠脉流出液CK-MB活性降低,LS2-4组血清甲状腺激素水平升高,心肌TRα1 mRNA表达上调(P＜0.05).LS1组、LS2组、LS3组和LS4组的甲状腺激素血清水平随左旋甲状腺素钠剂量的增加逐渐升高(P＜0.05).与LS1组和LS2组相比,LS3组和LS4组冠脉流出液CK-MB活性升高,心肌HSP70表达下调(P＜0.05).结论 10 μg/100 g左旋甲状腺素钠胃内灌注预处理可减轻大鼠心肌缺血再灌注损伤,且不会导致甲状腺激素水平升高,其机制可能与心肌HSP70和MHCα mRNA表达上调有关.

Abstract：

Objective To investigate the effects of preconditioning with different doses of levothyroxine sodium on myocardial ischemia-reperfusion (I/R) injury in immature rats. Methods Forty-eight female immature Wistar rats, aged 35 days, weighing 120-140 g, were randomly allocated into 6 groups ( n = 8 each): control group (group C), I/R group, and preconditioning with levothyroxine sodium 10, 20, 40 and 80 μg/100 g groups (groups LS1-4 ) . The rats received levothyroxine sodium 10, 20, 40 and 80 μg/100 g through a gastric tube every day for 7 days in groups LS1-4 , respectively. Venous blood samples were taken on 8th day for determination of serum thyroid hormone levels. The hearts were removed from the animals and perfused in a Langendorff apparatus with K-H solution saturated with 95% O2-5% CO2 at 37 ℃. The hearts were continuously perfused for 80 min in group C. After 30 min of equilibration, the isolated hearts were subjected to 20 min of ischemia followed by 30 min of reperfusion in I/R and LS1-4 groups. HR, SP and ± dp/dtmax were recorded at 20 min of perfusion and 30 min of reperfusion. The recovery rates of HR, SP and ± dp/dtmax were calculated at 30 min of reperfusion. The coronary effluent was collected at 10 min of perfusion and 15 min of reperfusion for determination of creatine kinase (CKMB) activity. The samples of ventricular myocardial tissues were taken at 30 min of reperfusion to detect the expression of heat shock protein 70 (HSP70), thyroid hormone receptor (TR) mRNA (TRa, , TRoj and TRft ) and myosin heavy chain (MHC) mRNA. Results Compared with group C, the recovery rates of HR, SP and. ± dp/dtmax were significantly decreased, the CK-MB activity was significantly increased, and MHCα mRNA expression was down-regulated in group I/R, the recovery rates of SP and ± dp/dtmax were significantly decreased, the CK-MB activity was significantly increased, and the expression of HSP70 and MHCα mRNA was up-regulated in groups LS1-4, and the serum thyroid hormone level was significantly increased and the expression of TRa, mRNA was up-regulated in groups LS2-4 ( P ＜ 0.05) . Compared with group I/R, the recovery rates of HR and ± dp/dtmax were significantly increased, the pression of HSP70 and MHCa mRNA was up-regulated, and the MHCJ3 mRNA expression was down-regulated in groups LS1-4 the CK-MB activity was significantly decreased in groups LS1-3, and the serum thyroid hormone level was significantly increased and the expression of TRα1, mRNA was up-regulated in groups LS2-4 ( P ＜ 0.05) . The serum thyroid hormone level increased gradually with the increase in the dose of levothyroxine sodium in groups LS1-4 ( P ＜ 0.05) . The CK-MB activity was significantly higher, while the HSP70 expression lower in groups LS3-4 than in groups LS1-2 (P ＜ 0.05). Conclusion Preconditioning with levothyroxine sodium 10 μg/100 g can alleviate the myocardial I/R injury in immature rats and does not lead to the increase in the level of thyroid hormone, and the up-regulation of HSP70 and MHCa mRNA expression may be involved in the mechanism.     

辛伐他汀预处理对肢体缺血再灌注诱发肺损伤大鼠肺组织血红素加氧酶-1表达的影响

目的 评价辛伐他汀预处理对肢体缺血再灌注诱发肺损伤大鼠肺组织血红素加氧酶-1(HO-1)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):假手术组(S组)、肢体缺血再灌注组(IR组)、辛伐他汀1、5、10 mg/kg组(S1组、S2组、S3组)和辛伐他汀对照组(SC组).采用夹闭股动脉2 h,再灌注3 h的方法制备肢体缺血再灌注模型.S组:仅分离股动脉和股静脉,不夹闭;IR组:制备肢体缺血再灌注模型;S1组、S2组、S3组:分别将辛伐他汀1、5、10 mg/kg溶于1 ml蒸馏水,于每13清晨灌胃1次,连续灌胃3 d后制备肢体缺血再灌注模型;SC组:辛伐他汀10 mg/kg溶于1 ml蒸馏水,于每日清晨灌胃1次,连续灌胃3 d.再灌注3 h时取颈动脉血样,行血气分析,记录PaO2和PaCO2,随后处死大鼠,取肺组织,观察病理学结果,计算湿重/干重比(W/D比),测定SOD活性,计数PMN,测定HO-1 mRNA及其蛋白的表达水平.结果 与S组比较,IR组PaO2及PaCO2降低,IR组、S1组和S2组肺组织W/D比和PMN计数升高,SOD活性降低(P＜0.05),S3组和SC组上述指标差异无统计学意义(P＞0.05),IR组、S1组、S2组、S3组和SC 组肺组织H0-1 mRNA及其蛋白表达上调(P＜0.01);与IR组比较,S1组、S2组和S3组PaO2、PaCO2及肺组织SOD活性升高,肺组织W/D比和PMN计数降低,肺组织HO-1 mRNA及其蛋白表达上调(P＜0.05或0.01);S1组、S2组和S3组肺组织WID比和PMN计数依次降低,SOD活性依次升高,HO-1 mRNA及其蛋白表达依次上调(P＜0.05或0.01).S1组、S2组和S3组肺组织病理性损伤较IR组减轻.结论 辛伐他汀预处理可上调肢体缺血再灌注大鼠肺组织HO-1的表达,从而产生肺保护作用,且呈剂量依赖性.

Abstract：

Objective To investigate the effects of simvastatin preconditioning on the pulmonary heme oxygenase-1 (HO-1) expression in rats with lung injury induced by ischemia-reperfusion (I/R) of hind limbs. Methods Forty-eight adult male SD rats weighing 250-300 g were randomly divided into 6 groups ( n = 8 each) : sham operation group (group S) ; I/R group; I/R + simvastatin 1,5, 10 mg/kg groups (S1 , S2, S3 groups) ; simvastatin control group (group SC) . I/R of hind limbs was produced by occlusion of bilateral femoral arteries for 2 h followed by 3 h reperfusion. Croups S1 , S2 , S3 received simvastatin 1, 5, 10 mg/kg respectively via an oro-gastric tube for 3 days before I/R. Group SC received simvastatin 10 mg/kg via an oro-gastric tube for 3 days. Arterial blood samples were taken at 3 h of reperfusion for blood gas analysis and PaO2 and PaCO2 were recorded. The animals were then sacrificed and the lungs removed immediately for pathologic examination and determination of the wet/dry lung weight ratio (W/D ratio), superoxide dismutase (SOD) activity and polymorphonuclear neutrophil (PMN) count . Hie expression of HO-1 mRNA and protein in lung tissues was detected using RT-PCR and Western blot analysis respectively.Results Alveolar edema, localized pulmonary atelectasis and large amount of PMN infiltration were found in I/R group and were ameliorated in S1, S2, S3 groups. Compared with group S, PaO2 and PaCO2 were significantly decreased in I/R group, W/D ratio and PMN count were increased and SOD activity was significantly decreased in I/R, S1 , S2 groups, and expression of HO-1 mRNA and protein was up-regulated in the other five groups ( P ＜ 0.05). PaO2, PaCO2 and SOD activity were significantly increased, W/D ratio and PMN count were significantly decreased, and HO-1 mRNA and protein expression was up-regulated in S1, S2 and S3 groups as compared with I/R group ( P ＜ 0.05 or 0.01). W/D ratio and PMN count were gradually decreased, SOD activity was gradually increased, and HO-1 mRNA and protein expression was gradually up-regulated in S1, S2 and S3 groups. Conclusion Simvastatin preconditioning has protective effect against lung injury induced by I/R of hind limbs in rats through up-regulation of HO-1 expression in the lung tissues and in a dose-dependent manner.     

重复高压氧预处理对大鼠脊髓缺血再灌注时低氧诱导因子-1α及促红细胞生成素表达的影响

目的 探讨重复高压氧预处理对大鼠脊髓缺血再灌注时低氧诱导因子-1α(HIF-1α)和促红细胞生成素(EPO)表达的影响.方法 雄性SD大鼠48只,体重250～300g,采用随机数字表法,将其随机分为3组(n=16):假手术组(S组)、脊髓缺血再灌注组(I/R组)和重复高压氧预处理(HOP组).HOP组实施高压氧预处理,参数为:氧浓度＞98%,氧含量1000ml/L,压力2.5 ATA,1 h/d,连续5 d,最后1 d处理后24 h,I/R组和HOP组采用夹闭腹主动脉20min再开放的方法制备脊髓缺血再灌注模型.再灌注48h时评价后肢运动功能,然后处死大鼠,取L5-7节段脊髓组织,测定HIF-1α、EPO的mRNA及其蛋白表达水平,光镜下观察病理学结果.结果 与S组比较,I/R组和HOP组后肢运动功能和脊髓前角正常运动神经元计数降低,脊髓组织HIF-1α、EPO的mRNA及其蛋白表达水平上调(P＜0.05);与I/R组比较,HOP组后肢运动功能和脊髓前角正常运动神经元计数升高,脊髓组织HIF-1α及EPO的mRNA及其蛋白表达水平上调(P＜0.05).HOP组脊髓组织病理学损伤程度轻于I/R 组.结论 重复高压氧预处理可上调HIF-1α及EPO表达,从而减轻大鼠脊髓缺血再灌注损伤.

Abstract：

Objective To investigate the effect of repeated hyperbaric oxygen preconditioning (HOP) on the expression of hypoxia-inducible factor-1 alpha (HIF-1a) and erythropoietin (EPO) following spinal ischemiareperfusion (I/R) in rats. Methods Forty-eight male SD rats weighing 250-300 g were randomly divided into 3 groups (n = 16 each): sham operation group (S group); I/R group and repeated HOP group (HOP group). The animals in HOP group were pretreated with O2 ( ＞ 98 % ) at 2.5 ATA I h/d for 5 consecutive days at 24 h before spinal cord I/R. The animals were anesthetized with intraperitoneal pentobarbital sodium 35 mg/kg. Spinal cord ischemia was produced by cross-clamping of abdominal aorta distal to renal artery for 20 min in I/R and HOP groups. Hind-limb motor function was assessed and scored st 48 h of reperfusion. The animals were then sacrificed and the L5-7 segment of the spinal cord was removed for determination of the expression of HIF-1 α and EPO mRNA and protein and microscopic examination. Results Compared with group S, the hind-limb motor function scores and the number of normal motor neurons in the anterior horn of the spinal cord were significantly decreased, and the expression of HIF-1α and EPO mRNA and protein was up-regulated in I/R and HOP groups ( P ＜ 0.05). Compared with group I/R, the hind-limb motor function scores and the number of normal motor neurons in the anterior horn of the spinal cord were significantly increased, and the expression of HIF-1α and EPO mRNA and protein was up-regulated in group HOP ( P ＜ 0.05). The spinal cord injury was attenuated in group HOP compared with group I/R. Conclusion Repeated HOP can reduce the spinal cord I/R injury though up-regulating the expression of HIF1α and EPO in rats.     

细胞穿透肽PEP-1介导血红素加氧酶-1对大鼠肠缺血再灌注损伤的影响

目的 评价细胞穿透肽PEP-1介导血红素加氧酶-1(HO-1)对大鼠肠缺血再灌注损伤的影响.方法 雄性SD大鼠18只,周龄7～9周,体重210～260 g,采用随机数字表法,将大鼠随机分为3组(n=6):假手术组(S组)、肠缺血再灌注组(IR组)和融合蛋白PEP-1/HO-1+肠缺血再灌注组(HO组).采用夹闭肠系膜上动脉45 min,恢复灌注120 min的方法制备大鼠肠缺血再灌注损伤模型.HO组夹闭肠系膜上动脉前30 min,左侧髂静脉注射融合蛋白PEP-1/HO-1 0.5 mg,S组不夹闭肠系膜上动脉,余操作同IR组.于再灌注120 min时处死大鼠取小肠组织,称重后计算肠湿/干重比,测定丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性和HO-1活性,免疫组化法检测肠组织HO-1蛋白的表达,光镜下观察肠组织结构并进行损伤评分.结果 与S组比较,IR组和HO组肠湿/干重比和MDA含量升高,SOD活性降低,HO-1活性和蛋白表达水平升高,损伤评分升高(P＜0.05);与IR组比较,HO组肠湿/干重比、MDA含量降低,SOD活性升高,HO-1活性和蛋白表达水平升高,损伤评分降低(P＜0.05).HO组大鼠肠组织病理学损伤较IR组减轻.结论 细胞穿透肽PEP-1可将HO-1成功导人大鼠肠组织中的细胞并减轻肠缺血再灌注损伤.

Abstract：

Objective To investigate the effects of heme oxygenase-1 (HO-1) mediated by cell penetrating peptide PEP-1 on intestinal ischemia/reperfusion (I/R) injuiy in tats. Methods Eighteen male SD rats aged 7-9 weeks weighing 210-260 g were randomly divided into 3 groups (re = 6 each): sham operation group (group S) , I/R group and PEP-1/HO-1 + I/R group (group HO) . To establish a model of intestinal I/R injury, intestines were exteriorized and the superior mesenteric artery was exposed and occluded for 45 min ischemia, and then the clamp was removed for 120 min reperfusion. The PEP-1/HO-1 fusion protein 0.5 mg was injected via the left iliac vein 30 min prior to ischemia in group HO. The superior mesenteric artery was exposed but not occluded in group S. At the end of reperfusion, the rats were sacrificed and intestinal tissues obtained to determine the intestinal wet/ dry ratio, malondialdehyde (MDA) level, activities of superoxide dismutase (SOD) and HO-1, and HO-1 protein expression. The histological changes in the intestinal mucosa were examined and the injuiy was scored. Results Compared with group S, the intestinal wet/dry ratio, MDA level, HO-1 activity, HO-1 protein expression and injury score were significantly increased, while the SOD activity was significantly decreased in groups I/R and HO ( P ＜ 0.05) . Compared with group I/R, the intestinal wet/dry ratio, MDA level and injury score were significantly decreased, while the SOD activity, HO-1 activity and HO-1 protein expression increased in group HO ( P ＜ 0.05) . The pathologic changes were significantly attenuated in group HO compared with group I/R.Conclusion HO-1 protein can be successfully delivered into intestinal tissues by PEP-1 and has protective effects against intestinal I/R injury.     

Effect of isoflurane on expression of IL-1β mRNA,IL-6 mRNA and TNF-α mRNA In the hippocamapus of immature rats

Obiective To investigate the effect ofisoflurane on expression of IL-1β mRNA,IL-6 mRNA and TNF-α mRNA in the hippocampus of immature rats.Methods sixty-four 7-clay-old SD rats were randomly assigned into 2 groups(n=32 each):control group(group C)and isoflurane group(group S).group S was exposed to 1.5% isoflurane for 6 h while group C to air.Fore animals were killed before anesthesia(T0,baseline),at 2,4,6 h(T1-3)of isoflurane anesthesia and 4,6,12 and 24 h after anesthesia(T4-7).The hippocampi were immediately removed for determimation of the expression of IL-1β mRNA,IL-6 mRNA and TNF-α mRNA by RT-PCR.Results Compared with group C,the expression of IL-1β mRNA at T1-5,IL-6 mRNA at T2.3 and TNF-α mRNA at T1-6 in the hippocampus was upregulated in group S.Conclusion The expression of IL-1β mRNA,IL-6 mRNA and TNF-β mRNA was elevated in the hippocampus of immature rats after being exposed to isoflurane.     

Effect of isoflurane on expression of IL-1β mRNA,IL-6 mRNA and TNF-α mRNA In the hippocamapus of immature rats

Obiective To investigate the effect ofisoflurane on expression of IL-1β mRNA,IL-6 mRNA and TNF-α mRNA in the hippocampus of immature rats.Methods sixty-four 7-clay-old SD rats were randomly assigned into 2 groups(n=32 each):control group(group C)and isoflurane group(group S).group S was exposed to 1.5% isoflurane for 6 h while group C to air.Fore animals were killed before anesthesia(T0,baseline),at 2,4,6 h(T1-3)of isoflurane anesthesia and 4,6,12 and 24 h after anesthesia(T4-7).The hippocampi were immediately removed for determimation of the expression of IL-1β mRNA,IL-6 mRNA and TNF-α mRNA by RT-PCR.Results Compared with group C,the expression of IL-1β mRNA at T1-5,IL-6 mRNA at T2.3 and TNF-α mRNA at T1-6 in the hippocampus was upregulated in group S.Conclusion The expression of IL-1β mRNA,IL-6 mRNA and TNF-β mRNA was elevated in the hippocampus of immature rats after being exposed to isoflurane.     

Protective effect of ischemic postconditioning on lung ischemia-reperfusion injury in rats and the role of heme oxygenase-1

To investigate the effect of ischemic postconditioning (IPO) on acute lung ischemia-reperfusion (I/R) injury and the protein expression of haeme oxygenase-1 (H0-1), a cytoprotective defense against oxidative injury. Methods: After being anesthetized with chloralhy-drate, forty-eight healthy SD rats were randomly divided into 6 groups (8 in each): sham operation group (S group); I/R group: left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group: left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Hemin (HM)+ I/R group: hemin, an inducer of HO- 1 was injected intraperitoneally at 40 μmol.kg-1·day-1 for two con-secutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX+IPO group: zinc protoporphyrin Ⅸ, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM+S group: HM was administered as in the HM+I/R group without inducing lung I/R. Arterial partial pressure of oxygen (PaO2) and malondialdehyde (MDA) content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-his-tochemical technique and for light microscopic examination. Results: The PaO2 was significantly lower in all the experimental groups compared with sham group (90 mm Hg ±11 mm Hg). However, the values ofPaO2 in IPO (81 mm Hg ±7 mm Hg) and HM+I/R (80 mm Hg±9 mm Hg) were higher than that in I/R (63 mm Hg±9 mm Hg) and ZnPPIX+IPO (65 mm Hg±8 mm Hg) groups (P<0.01). The protein expression of HO-1 in lung tissue was significantly increased in I/R group compared with S group (P<0.01). While the HO-1 protein expression was higher in IPO and HM+I/R groups as compared with I/R group (P<0.05, P<0.01). The lung wet/ dry (W/D) weight ratio and MDA content in serum were significantly increased in I/R group as compared with S or HM+S groups (P<0.01), accompanied by severe lung tissue histological damage, which was attenuated either by IPO or by HM pretreatment (P<0.01, IPO or HM+I/R vs. I/R). The protective effect of IPO was abolished by ZnPPIX. Condusion: Ischemic postconditioning can attenuate the lung ischemia-reperfusion injury through upregulating the protein expression of HO-1 that leads to reduced post-ischemic oxidative damage.     

缺血预处理联合后处理对大鼠肾缺血再灌注损伤的影响

目的 评价缺血预处理联合后处理对大鼠肾缺血再灌注损伤的影响.方法 健康雄性SD大鼠30只,体重250～280 g,随机分为5组(n=6):假手术组(S组)、缺血再灌注组(I/R组)、缺血预处理组(IP组)、缺血后处理组(IPo组)和缺血预处理联合后处理组(IP+IPo组).S组仅开腹,游离双侧肾脏,分离双侧肾蒂但不夹闭.采用夹闭双侧肾蒂45 min、再灌注6 h的方法 制备肾缺血再灌注模型.IP组夹闭双侧肾蒂5 min,再灌注5 min,反复3次,余操作同I/R组;IPo组夹闭双侧肾蒂45 min后,再灌注10 8,缺血10 s,反复3次,再灌注6 h.于再灌注6 h时,经心脏抽血后迅速处死大鼠取肾,测定血清肌酐(Cr)和尿素氮(BUN)的浓度;采用硫代巴比妥酸法测定肾组织丙二醛(MDA)含量,采用黄嘌呤氧化酶法测定肾组织超氧化物歧化酶(SOD)活性;光镜下观察肾组织病理学结果 ;TUNEL法检测肾组织凋亡细胞,计算凋亡指数(AJ).结果 与S组比较,其余各组血清Cr和BUN的浓度升高,肾组织SOD活性降低,MDA含量和AI升高(P<0.05);与I/R组比较,IP组、IPo组和IP+IPo组血清Cr和BUN的浓度降低,肾组织SOD活性升高,MDA含量和AJ降低(P<0.05),肾损伤减轻;与IP组和IPo组比较,IP+IPo组肾组织SOD活性升高,AI降低(P<0.05),肾损伤减轻.结论 缺血预处理联合后处理可减轻大鼠肾缺血再灌注损伤,较单独应用时效果好.     

mito-KATP通道在缺血后处理减轻大鼠肾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(mito-KATP通道)在缺血后处理减轻大鼠肾缺血再灌注损伤中的作用.方法 健康成年雄性SD大鼠35只,体重250～280 g,随机分为5组(n=7):假手术组(S组)仅分离双侧肾蒂,暴露45 min不夹闭;肾缺血再灌注组(I/R组)夹闭双侧肾蒂缺血45 min,再灌注6 h制备大鼠肾缺血再灌注模型;缺血后处理组(Ipo组)夹闭双侧肾蒂缺血45 min,再灌注10 s,缺血10 s,反复3次,再灌注6 h;mito-KATP通道阻断剂5-羟葵酸+I/R组(5-HD+I/R组)缺血前30 min腹腔注射5-HD 10 mg/kg,余处理同I/R组;缺血后处理+5-HD组(5-HD+Ipo组)缺血前30 min腹腔注射5-HD 10 mg/kg,余处理同Ipo组.于再灌注6 h时采集心脏血样,取肾并分离肾小管上皮细胞,测定血清Cr和BUN的浓度、肾小管上皮细胞线粒体膜电位、细胞内活性氧(ROS)含量和游离Ca2+浓度.结果 与S组比较,I/R组、Ipo组、5-HD+I/R组和5-HD+Ipo组血清Cr和BUN的浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量升高,线粒体膜电位降低(P＜0.05);与I/R组比较,Ipo组血清Cr和BUN的浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量降低,线粒体膜电位升高(P＜0.05),5-HD+I/R组和5-HD+Ipo组上述指标差异无统计学意义(P＞0.05);与Ipo组比较,5-HD+I/R组和5-HD+Ipo组血清Cr和BUN浓度、肾小管上皮细胞内游离Ca2+浓度和ROS含量升高,线粒体膜电位降低(P＜0.05).结论 mito-KATP通道的开放参与了缺血后处理减轻大鼠肾缺血再灌注损伤的过程.     

臭氧氧化预处理对大鼠肾缺血再灌注损伤的热休克蛋白表达的影响

目的 探讨臭氧氧化预处理通过诱导热休克蛋白70(HSP70)的合成,保护大鼠肾脏缺血再灌注损伤的作用与机制.方法 建立原位大鼠单侧肾缺血再灌注动物模型,I/R前15 d经直肠吹入氧气和臭氧的混合气体5.0～5.5 ml(臭氧浓度50 mg/L,1 mg/kg体蕈,每日 1次).全自动生化分析仪检测尿素氮(BUN)、肌酐(Cr),比色法测定血清的脂质过氧化产物丙二醛(MDA)、超氧化物歧化酶(SOD).Western blot检测HSP70蛋白的含量;逆转录聚合酶链反应(RT-PCR)方法检测HSP70的表达.结果 肾缺血再灌注24 h后,血清中BUN、Cr、MDA明显增高,肾组织内HSPT0表达明显增强(P<0.05),经臭氧氧化预处理后,血清中的BUN、Cr、MDA均降低,SOD升高;HSP70表达升高更加明显(P<0.05).结论 臭氧氧化预处理可以诱导大鼠肾缺血再灌注组织中HSP70表达,减轻大鼠肾脏缺血再灌注损伤.     

臭氧氧化预处理对大鼠肾缺血再灌注损伤的热休克蛋白表达的影响

目的 探讨臭氧氧化预处理通过诱导热休克蛋白70(HSP70)的合成,保护大鼠肾脏缺血再灌注损伤的作用与机制.方法 建立原位大鼠单侧肾缺血再灌注动物模型,I/R前15 d经直肠吹人氧气和臭氧的混合气体5.0～5.5 ml(臭氧浓度50 mg/L,1 mg/kg体重,每日1次).全自动生化分析仪检测尿素氮(BUN)、肌酐(Cr),比色法测定血清的脂质过氧化产物丙二醛(MDA)、超氧化物歧化酶(SOD).Western blot检测HSP70蛋白的含量;逆转录-聚合酶链反应(RT-PCR)方法检测HSPT0的表达.结果 肾缺血再灌注24 h后,血清中BUN、Cr、MDA明显增高,肾组织内HSP70表达明显增强(P＜0.05),经臭氧氧化预处理后,血清中的BUN、Cr、MDA均降低,SOD升高;HSP70表达升高更加明显(P＜0.05).结论 臭氧氧化预处理可以诱导大鼠肾缺血再灌注组织中HSP70表达,减轻大鼠肾脏缺血再灌注损伤.     

Roles of MAPKAPK-2 and HSP27 in the reduction of renal ischemia–reperfusion injury by ischemic postconditioning in rats

Purpose

Ischemic postconditioning is a procedure during which intermittent reperfusions are performed in the early phase of reperfusion to protect organs from ischemia/reperfusion injury. And in this study, we mainly investigated the injury-alleviative role of mitogen-activated protein kinase-activating protein kinase-2 (MAPKAPK-2) and heat shock protein 27 (HSP27) in renal ischemic reperfusion injury during the procedure of ischemic postconditioning.

Methods

Sprague-Dawley rats were randomly divided into four groups. The injury models were prepared by clipping the left renal pedicle of rats after ligating the right renal pedicle for 60 min. In the ischemic postconditioning group, sequential reperfusions were done for 10 s and another ischemia for 10 s for six cycles after kidney ischemia for 60 min. In addition, the specific inhibitor SB203580 was injected through caudal vein before ischemia. Serum creatinine, blood urea nitrogen and the expression of HSP27 and MAPKAPK-2 were detected 1, 3, 6 and 24 h later after reperfusion. Furthermore, phosphorylation of HSP27 and MAPKAPK-2 protein contents, histological changes and apoptosis were compared 24 h later after reperfusion.

Results

Our data showed that ischemic postconditioning attenuated the renal dysfunction and cell apoptosis induced by I/R and increased phosphorylation of MAPKAPK-2 and HSP27. The results indicated that ischemic postconditioning decreased apoptosis and improved renal function.

Conclusions

Taken together, it is suggested that the renal protective effect may be related to the levels of HSP27 and MAPKAPK-2 activation.     

缺血后处理对大鼠肝缺血再灌注时肝细胞线粒体膜通透性转换和膜电位的影响

目的 评价缺血后处理对大鼠肝缺血再灌注时肝细胞线粒体膜通透性转换和膜电位(△Ψm)的影响.方法 成年健康雄性SD大鼠40只,体重220～260 g,采用随机数字表法,将其随机分为5组(n=8):假手术组(S组)、苍术苷+假手术组(A+S组)、缺血再灌注组(IR组)、缺血后处理组(IPO组)和苍术苷+缺血后处理组(A+IPO组).采用阻断肝中叶和左叶60 min,恢复血流灌注6 h的方法 建立大鼠肝缺血再灌注模型.S组和A+S组仅游离肝门,不阻断血管;A+S组关腹前静脉注射苍术苷5 mg/kg;IR组制备肝缺血再灌注模型;IPO组于再灌注前行缺血后处理,再灌注1 min,缺血1 min,反复3次;A+IPO组于再灌注前静脉注射苍术苷5 mg/kg.于缺血前即刻和再灌注6 h时,采集左颈静脉血样,测定血清ALT和AST的活性.再灌注6 h时处死大鼠,取肝左叶组织,观察超微结构和细胞凋亡情况,计算凋亡指数,测定细胞色素c(Cyt c)的表达水平、△Ψm和线粒体通透性转换孔(MPTP)活性.结果 与S组比较,A+S组时血清ALT和AST的活性、凋亡指数、Cyt c表达、△Ψm和MPTP活性差异无统计学意义(P＞0.05),IR组、IPO组和A+IPO组再灌注6 h时血清ALT和AST的活性、凋亡指数升高,Cyt c表达上调,△Ψm降低,MPTP活性升高(P＜0.05);与IR组比较,IPO组血清ALT和AST的活性、凋亡指数降低,Cyt c表达下调,△Ψm升高,MPTP活性降低(P＜0.05),肝组织病理学损伤减轻,A+IPO组各指标差异无统计学意义(P＞0.05);与IPO组比较,A+IPO组血清ALT和AST的活性、凋亡指数升高,Cyt c表达上调,△Ψm降低,MPTP活性升高(P＜0.05),肝组织病理学损伤加重.结论 缺血后处理可抑制肝细胞线粒体膜通透性转换,减少线粒体△Ψm的耗散,从而减轻大鼠肝缺血再灌注损伤.

Abstract：

Objective To investigate the effects of ischemic postconditioning on mitochondrial permeability transition and mitochondrial transmembrane potential(△Ψm)following hepatic ischemia-reperfusion(I/R)in rats.Methods Forty male SD rats weighing 220-260 g were randomly divided into 5 groups with 8 animals in each group:sham operation group(group S);atractyloside+sham operation group(group A+S);I/R group;ischemic postconditioning group(group IPO)and atractyloside+ischemic postconditioning group(group A+IPO).The animals were anesthetized with intramuscular injection of atropine 0.05 mg/kg.Hepatic I/R was produced by occlusion of hepatic blood flow for 60 min followed by 6 h reperfusion.In group A+S,atractyloside 5 mg/kg was injected intravenously before abdomen Was closed.In group IPO,the animals were subjected to 3 cycles of 1 min reperfusion interspersed with 1 min hepatic isehemia at the end of 60 min hepatic ischemia.In group A+IPO,atractyloside 5 mg/kg was injected intravenously before reperfusion. Venous blood samples were collected for determination of serum ALT and AST activities immediately before ischemia and at 6 h of reperfusion. The animals were then sacrificed.Their livers were removed for microscopic examination, detection of apoptosis and determination of cytochrome c (Cyt c) expression, △Ψm and mitochonerial permeability transition pore (MPTP)activity. Apoptosis index (AI) was calculated. Results There was no significant difference in serum ALT and AST activities, AI, Cyt c expression, △Ψm and MPTP activity between S and A + S groups (P＞0.05). Compared with group S, serum ALT and AST activities and AI were significantly increased, Cyt c expression was up-regulated, △Ψm was decreased and MPTP activity was increased in groups I/R, IPO and A+IPO(P＜0.05).Compared with group I/R, serum ALT and AST activities and AI were significantly decreased,Cyt c expression was down-regulated, △Ψm was increased and MPTP activity was decreased in group IPO(P＜0.05), while no significant change was found in group A+IPO(P＞0.05).Compared with group IPO,serum ALT and AST activities and AI were significantly increased, Cyt c expression was up-regulated, △Ψm was decreased and MPTP activity was increased in group A + IPO(P＜ 0.05).Microscopic examination showed that hepatic injury was reduced in group IPO compared with group I/R, while aggravated in group A+ IPO compared with group IPO. Conclusion Ischemic postconditioning can protect liver from I/R injury by attenuating the I/R-induced increase in MPTP opening and decrease in △Ψm in rats.     

缺血后处理减轻犬肾缺血再灌注损伤的作用

目的 探讨缺血后处理减轻犬肾缺血再灌注损伤的作用及其相关机制.方法 随机将犬分为假手术组、缺血再灌注组和缺血后处理组,每组5只.假手术组:犬麻醉后,取其腹正中切口进入腹腔,游离双侧肾脏,切除右肾后,关腹.缺血再灌注组:手术操作与假手术组相同,仅在切除右肾和游离左肾之后,将左肾动、静脉夹闭60 min,然后开放血管.缺血后处理组:手术操作与缺血再灌注组相同,仅在肾动、静脉被夹闭60 min后,以再灌注(开放血管)30 s、夹闭血管30 s为1个循环,共进行6次循环,然后完全放开血管.分别于术后24、48及72 h采集犬静脉血2 ml,使用全自动生化分析仪测定各组犬血清肌酐(Cr)和尿素氮(BIJN)水平;术后第3天取犬肾组织,采用硫代巴比妥酸法测定丙二醛(MDA)含量,采用黄嘌呤氧化酶法测定超氧化物歧化酶(SOD)活性,采用化学比色法测定髓过氧化物酶(MPO)活性,并观察犬肾组织的病理改变和细胞凋亡情况.结果 术后各时间点,缺血再灌注组、缺血后处理组和假手术组犬的血清Cr和BUN水平均依次降低,3组间比较,差异均有统计学意义(P<0.05).术后第3天,缺血再灌注组、缺血后处理组和假手术组犬肾组织中SOD活性依次升高,而MDA含量和MPO活性均依次降低,3组间比较,差异均有统计学意义(P<0.05).假手术组肾小球和肾小管结构正常,未见明显病理改变;缺血再灌注组肾间质水肿,大量炎症细胞浸润,肾小管上皮细胞刷状缘消失,大量上皮细胞坏死、脱落,管腔扩张,其中可见大量管型;缺血后处理组可见肾间质轻度水肿,肾小管上皮细胞扁平,部分刷状缘消失、坏死,偶见管型,管周血管有少量淤血.假手术组、缺血再灌注组、缺血后处理组犬肾的细胞凋亡指数分别为2.7±1.3、28.4±6.2和15.4±4.1,3组间比较,差异均有统计学意义(P<0.05).结论 缺血后处理能减轻犬肾缺血再灌注损伤,其机制可能与缺血后处理减少氧自由基的产生、抑制细胞凋亡及减少炎症细胞浸润有关.     

Protective effect of ischemic postconditioning on lung ischemia-reperfusion injury in rats and the role of heme oxygenase-1

To investigate the effect of ischemic postconditioning (IPO) on acute lung ischemia-reperfusion (I/R) injury and the protein expression of haeme oxygenase-1 (H0-1), a cytoprotective defense against oxidative injury. Methods: After being anesthetized with chloralhy-drate, forty-eight healthy SD rats were randomly divided into 6 groups (8 in each): sham operation group (S group); I/R group: left lung hilum was clamped for 40 minutes followed by 105 minutes of reperfusion; IPO group: left lung hilum was clamped for40 minutes and postconditioned by 3 cycles of 30 seconds of reperfusion and 30 seconds of reocclusion; Hemin (HM)+ I/R group: hemin, an inducer of HO- 1 was injected intraperitoneally at 40 μmol.kg-1·day-1 for two con-secutive days prior to 40 minutes clamping of left lung hilum; ZnPPIX+IPO group: zinc protoporphyrin Ⅸ, an inhibitor of HO-1 was injected intraperitoneally at 20 mg·kg-1 24 hours prior to 40 minutes clamping of left lung hilum; and HM+S group: HM was administered as in the HM+I/R group without inducing lung I/R. Arterial partial pressure of oxygen (PaO2) and malondialdehyde (MDA) content in serum were assessed. The left lung was removed for determination of wet/dry lung weight ratio and expression of HO-1 protein by immuno-his-tochemical technique and for light microscopic examination. Results: The PaO2 was significantly lower in all the experimental groups compared with sham group (90 mm Hg ±11 mm Hg). However, the values ofPaO2 in IPO (81 mm Hg ±7 mm Hg) and HM+I/R (80 mm Hg±9 mm Hg) were higher than that in I/R (63 mm Hg±9 mm Hg) and ZnPPIX+IPO (65 mm Hg±8 mm Hg) groups (P<0.01). The protein expression of HO-1 in lung tissue was significantly increased in I/R group compared with S group (P<0.01). While the HO-1 protein expression was higher in IPO and HM+I/R groups as compared with I/R group (P<0.05, P<0.01). The lung wet/ dry (W/D) weight ratio and MDA content in serum were significantly increased in I/R group as compared with S or HM+S groups (P<0.01), accompanied by severe lung tissue histological damage, which was attenuated either by IPO or by HM pretreatment (P<0.01, IPO or HM+I/R vs. I/R). The protective effect of IPO was abolished by ZnPPIX. Condusion: Ischemic postconditioning can attenuate the lung ischemia-reperfusion injury through upregulating the protein expression of HO-1 that leads to reduced post-ischemic oxidative damage.     

细胞凋亡抑制参与联合应用吗啡和肢体远隔缺血后处理的心肌保护作用

目的 探讨抗细胞凋亡在联合应用吗啡和肢体远隔缺血后处理(remote ischemic postconditioning,RIP)心肌保护中的作用. 方法 采用大鼠在体心肌缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)模型,根据随机数字表法将60只SD大鼠分为4组(每组15只):缺血/再灌注(ischemia/reperfusion,I/R)组(I/R组)、肢体RIP组(RIP组)、吗啡后处理组(M组)以及联合应用吗啡和肢体RIP组(M+RIP组).再灌注末留取缺血中心区、缺血边缘区和非缺血区心肌组织标本,应用Tunel染色法检测心肌细胞凋亡指数(apoptotic index,AI),应用实时定量PCR技术检测心肌细胞凋亡相关基因Bcl-2 mRNA和Bax mRNA表达,光学和电子显微镜观察缺血中心区心肌细胞形态. 结果 I/R组、RIP组、M组和M+RIP组缺血中心区心肌细胞AI分别为(49.1±4.9)％、(34.2±2.9)％、(39.7±3.2)％和(29.0±4.9)％,缺血边缘区心肌细胞AI分别为(12.7±2.2)％、(8.2±1.6)％、(10.4±2.7)％和(5.9±1.4)％.在缺血中心区和缺血边缘区,M+RIP组心肌细胞AI较I/R组和M组明显降低(P＜0.05),M+RIP组的Bcl-2 mRNA表达较I/R组、RIP组和M组明显增强(P＜0.05),而M+RIP组的Bax mRNA表达则较I/R组、RIP组和M组明显降低(P＜0.05),M+RIP组的Bcl-2/Bax较I/R组、RIP组和M组明显升高(P＜0.05).光学和电子显微镜检查显示,M+RIP组的心肌形态和线粒体结构明显改善. 结论 Bcl-2相关信号通路的细胞凋亡抑制是联合应用吗啡和肢体RIP的心肌保护作用机制之一.