瑞芬太尼痛觉过敏大鼠Delta阿片受体mRNA的表达水平

目的：探讨切口痛-瑞芬太尼痛觉过敏大鼠背根神经节及海马Delta阿片受体mRNA表达水平的变化。方法：健康雄性SD大鼠32只,尾静脉置管后随机分为4组,瑞芬太尼组（R组）输注瑞芬太尼1μg·kg-1·min-1,切口痛组（I组）输注等体积生理盐水,甘氨酸组（G组）输注甘氨酸15μg·kg-1·min-1,对照组（C组）输注等体积生理盐水,最后一次痛阈测定后留取大鼠L4-L6背根神经节及海马标本,应用实时定量PCR方法测定Delta阿片受体mRNA的表达水平。结果：R组、I组、G组均发生痛觉过敏,且R组痛觉过敏的程度高于I组和G组;R组海马Delta阿片受体mRNA表达水平（4.359±1.031）显著高于C组、I组（2.373±1.014）和G组（2.411±0.326）（P＜0.05）;R组背根神经节Delta阿片受体mRNA表达水平（2.108±0.361）显著高于C组、I组（1.409±0.435）和G组（1.413±0.234）（P＜0.05）。结论：瑞芬太尼可在切口痛模型大鼠中引发痛觉过敏,其机制可能与背根神经节及海马Delta阿片受体mRNA表达上调有关。     

阿片受体在缺血预处理中的作用

目的　研究阿片受体激动在缺血预处理限制心肌梗死(心梗)范围作用中的地位。方法　建立在体家兔心脏缺血再灌注模型,观察阿片受体拮抗剂纳洛酮对缺血预处理心肌保护作用的影响。在离体兔心模型上,观察阿片受体激动剂吗啡代替短暂缺血刺激,对随后发生的急性心梗范围的影响,并用纳洛酮及蛋白激酶C阻断剂Chelerythrine分别进行干预。电镜观察吗啡预处理对离体心脏缺血心肌超微结构改变的影响。结果　在体心脏模型上,5min缺血及10min再灌注的预处理可显著缩小随后30min缺血引起的心梗范围(P＜0.01);在预处理前10min或30min、缺血前5min给予纳洛酮均可使预处理所产生的限制心梗范围的作用消失。离体心脏经历5min全心缺血及10min再灌注的预处理后,可缩小心梗范围(P＜0.05);在缺血前如给予吗啡预灌注15min,亦可缩小心梗范围(P＜0.05),其作用可被纳络酮或Chelerythrine分别阻断。30min缺血后心肌线粒体等超微结构严重受损,如给吗啡预灌流,心肌损伤明显减轻。结论　阿片受体激动参与了缺血预处理的心肌保护;吗啡预处理可以减轻缺血心肌损伤及产生限制心梗范围的心肌保护作用;吗啡是通过心脏局部的阿片受体介导,激活蛋白激酶C从而产生心肌保护作用。     

短暂缺血预处理减轻缺血性脑损伤的研究

目的 观察缺血预处理对再次脑缺血损伤的保护作用。方法 将SD大鼠分为3组，分别给予生理盐水右侧颈内动脉灌注（SI）、双侧颈总动脉夹闭（BCAO）和双侧颈总动脉夹闭并生理盐水右侧颈内动脉灌注（BS）。每次持续3min，间隔7min，反复3次，24h后作经插线右大脑中动脉栓塞（MCAO），观察MCAO后脑组织含水量、血脑屏障通透性（以脑伊文思蓝含量表示）后梗死体积。结果 BS组MCAO后24h和48h脑伊文思蓝（EB）含量和脑含水量明显较其他两组低（P＜0.01）；MCAO72hBS组脑梗死低于其它两组（P＜0.05）。结论 双侧颈总动脉夹闭并生理盐水右侧颈内动脉灌注对脑再次缺血有明显的保护作用。     

阿片受体介导心肌保护机制的研究

心肌阿片受体参与了缺血预处理对心脏的调节作用,阿片类物质通过激活心肌阿片受体能模拟缺血预处理对心脏的作用.心肌阿片受体的激活所产生的早期时相和后时相心肌保护作用的信号途径涉及Gi/Go、蛋白激酶C、酪氨酸激酶和ATP敏感钾离子通道等途径.在心脏外科手术或者冠心病等心脏病的治疗中应用阿片受体激动剂,并尝试联合其他心肌保护药物如莨宕碱类药物来保护心脏必将成为临床心肌保护的趋势和重要组成部分.     

外周和中枢阿片受体诱导心脏预处理保护作用及信号转导机制

前期的研究关于阿片类药物预处理的心肌保护效应,主要集中在心脏上的阿片受体在这种保护效应中的作用及信号机制.然而最新的研究已经发现通过中枢(侧脑室内,鞘内)注射吗啡预处理可以直接激活中枢阿片受体,同样可以模拟经典的缺血预处理(ischemia precondition,IPC)心肌保护效应,并且发现中枢神经系统3种阿片受体均参与介导了这种保护作用.这种保护作用的机制可能与痛觉的干预和神经递质的释放等效应有关.     

阿片受体介导心肌保护机制的研究

心肌阿片受体参与了缺血预处理对心脏的调节作用,阿片类物质通过激活心肌阿片受体能模拟缺血预处理对心脏的作用。心肌阿片受体的激活所产生的早期时相和后时相心肌保护作用的信号途径涉及G i/G o、蛋白激酶C、酪氨酸激酶和ATP敏感钾离子通道等途径。在心脏外科手术或者冠心病等心脏病的治疗中应用阿片受体激动剂,并尝试联合其他心肌保护药物如莨宕碱类药物来保护心脏必将成为临床心肌保护的趋势和重要组成部分。     

阿片受体在异氟醚延迟预处理减轻兔心肌缺血再灌注损伤中的作用

目的 探讨阿片受体在异氟醚延迟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2.0～2.5 kg,采用结扎左冠状动脉前降支40 min,再灌注120 min的方法制备心肌缺血再灌注损伤模型,随机分为4组(n=10):假手术组(S组)吸入纯氧2 h,24 h后仅动脉下穿线不结扎;心肌缺血再灌注组(IR组)吸入纯氧2 h,24 h后行心肌缺血再灌注;异氟醚延迟预处理组(I组)吸人2%异氟醚2 h,24 h后行心肌缺血再灌注;阿片受体阻断剂+异氟醚延迟预处理组(N组)静脉注射纳洛酮6 mg/kg后10 min,吸入2%异氟醚2 h,24 h后行心肌缺血再灌注.于再灌注120 min时取心脏,计算心肌缺血面积和梗死面积,测定磷酸化p38MAPK蛋白表达水平,观察心肌细胞超微结构.结果 S组心肌细胞完整,排列整齐,线粒体形态正常,糖原丰富;IR组和N组心肌细胞水肿,心肌纤维排列紊乱,线粒体、内质网膜水肿,空泡化;I组心肌细胞水肿程度减轻,心肌纤维排列较完整,线粒体轻度水肿.与IR组比较,I组心肌梗死面积减小,磷酸化p38MAPK蛋白表达下调(P<0.05),N组上述指标差异无统计学意义(P>0.05).结论 阿片受体参与异氟醚延迟预处理减轻兔心肌缺血再灌注损伤.     

外周和中枢阿片受体诱导心脏预处理保护作用及信号转导机制

The majority of investigations about the cardioprotection induced by opioid preconditioning was focused on the role played by myocardial opioid receptors and the of signal mechanism. However, it has been found that directly activation of the opioid receptors in the central nervous system by intracerebroventricular/intrathecal morphine preconditioning also could mimic cardioprotective effects induced by ischemia preconditioning against ischemia-reperfusion injury, one had found also, the k-,δ- andμ-ORs of central nervous system were implicated in modulating the protective effect. This effect was probably induced by neurohumoral and analgesic substances.     

外周和中枢阿片受体诱导心脏预处理保护作用及信号转导机制

The majority of investigations about the cardioprotection induced by opioid preconditioning was focused on the role played by myocardial opioid receptors and the of signal mechanism. However, it has been found that directly activation of the opioid receptors in the central nervous system by intracerebroventricular/intrathecal morphine preconditioning also could mimic cardioprotective effects induced by ischemia preconditioning against ischemia-reperfusion injury, one had found also, the k-,δ- andμ-ORs of central nervous system were implicated in modulating the protective effect. This effect was probably induced by neurohumoral and analgesic substances.     

阿片受体在异氟醚延迟预处理减轻兔心肌缺血再灌注损伤中的作用

Objective To investigate the role of opioid receptors in the protective effects of isoflurane-induced delayed preconditioning against myocardial ischemia-reperfusion (I/R) injury in rabbits. Methods Forty male New Zealand white rabbits weighing 2.0-2.5 kg were randomly assigned into 4 groups ( n = 10 each) : group I sham operation (S); group II I/R; group Ⅲ isoflurane + I/R (Iso) and group IV Iso + naloxone + I/R (Nal). Myocardial I/R was induced by 40 min occlusion of left anterior descending branch (LAD) of coronary artery followed by 120 min reperfusion. In group Ⅲ (Iso) 2% isoflurane in 100% O2 was inhaled for 2 h and I/R was produced 24 h later. In group IV (Nal) naloxone 6 mg/kg was given iv 10 min before 2 h of 2% isoflurane inhalation and I/R was produced 24 h later. At the end of 120 min reperfusion, infarct size (IS) and area at risk (AAR) were determined by Evan's blue and TTC staining. Myocardial ultrastructure was examined by electron microscopy. The phosphorylated p38MAPK protein expression in myocardium was determined by Western blot. Results The IS was significantly smaller in group Iso ( Ⅲ ) ( 19.7% ± 2.8%) than in I/R group ( II ) (37.8% ±1.7%) (P<0.05). The phosphorylated p38MAPK protein expression in myocardium was significantly lower in group Iso than in group I/R. Microscopic examination showed less myocardial damage in Iso group than in group I/R. The protective effects of delayed preconditioning by isoflurane was prevented by naloxone pretreatment. ConclusionOpioid receptors may be involved in the protective effects of delayed preconditioning by isoflurane against myocardial I/R injury.     

大鼠窒息性心跳停止复苏后脑缺血损伤模型的建立

目的建立稳定的窒息性心跳停止复苏后脑缺血损伤大鼠模型。方法 72只健康雄性SD大鼠随机均分为六组:假手术组(S组)和窒息组(C5、C6、C7、C8和C9组)。C5、C6、C7、C8、C9组分别在窒息5、6、7、8、9min后进行心肺复苏。记录各窒息组窒息到停循环时间、循环停止时间、自主循环恢复时间、复苏成功率、复苏后生命体征变化、神经功能缺损评分。复苏后第9天,观察海马CA1区神经元存活情况。结果窒息组均发生了循环停止,随着窒息时间延长,循环停止时间与自主循环恢复时间逐渐延长;C5组大鼠全部存活,C6、C7、C8和C9组大鼠复苏成功率分别为91.7%、83.3%、75.0%和33.3%,C9组复苏成功率低于其他各组(P<0.05);C5、C6、C7组复苏后各时点神经功能缺损评分高于C8和C9组(P<0.05)。复苏后第9天,与S组比较,C5、C6组海马CA1区神经元损伤不明显,C7组有少量神经元坏死,C8组和C9组大量神经元坏死(P<0.01)。结论窒息8min后进行心肺复苏能够建立稳定的脑损伤模型。     

缺氧预处理对异丙酚诱导新生大鼠大脑神经毒性的影响

目的探讨缺氧预处理对异丙酚诱导新生大鼠大脑神经毒性的影响。方法SPF级SD大鼠75只,日龄7 d,体重10~15 g,采用随机数字表法将其分为5组(每组15只):生理盐水组(N组),腹腔注射生理盐水100μl;脂肪乳剂组(F组),腹腔注射脂肪乳剂100μl;异丙酚组(P组),腹腔注射异丙酚100 mg/kg;缺氧预处理组(H组),大鼠置于8%氧浓度10 min,空气10 min,循环5次,空气中恢复2 h;缺氧预处理+异丙酚组(H+P组),先给予缺氧预处理(同H组),后给予异丙酚(同P组)。大鼠苏醒后时点,断头取海马组织:制作电镜标本,应用透射电镜观察各组海马神经细胞的超微结构;制作石蜡切片,行TUNEL法染色,检测TUNEL阳性细胞的数量;Western blot法检测活化的半胱氨酸蛋白酶-3(cleaved-caspase-3)、B淋巴细胞瘤-2(B-cell lymphoma-2,Bcl-2)和B淋巴细胞瘤-2相关X蛋白(B-cell lymphoma-2-associated X protein,Bax)蛋白水平。结果与N组比较,P组海马神经细胞萎缩、细胞器溶解、核仁消失,TUNEL阳性细胞数量明显增加(P<0.05),Bax蛋白和cleaved-caspase-3蛋白水平升高(P<0.05),Bcl-2蛋白水平降低(P<0.05)。与P组比较,H+P组海马神经细胞的细胞膜完整、细胞器和细胞核清晰可见、核染色质稍有减少,TUNEL阳性细胞数量减少(P<0.05),Bax蛋白和cleaved-caspase-3蛋白水平降低(P<0.05),Bcl-2蛋白水平升高(P<0.05)。结论缺氧预处理可以减轻异丙酚对大鼠发育期大脑的神经毒性,部分机制可能是上调海马神经细胞抗凋亡蛋白Bcl-2和下调促凋亡蛋白Bax、cleaved-caspase-3水平。     

低氧预处理对大鼠BMSCs葡萄糖代谢的影响

目的观察低氧预处理对BMSCs葡萄糖代谢的影响,探讨其潜在机制,为干细胞疗法的优化提供理论依据。方法取1～3日龄SD大鼠骨髓,采用密度梯度离心法获得BMSCs,取第4代细胞用于实验。根据处理方法不同将细胞分为4组:A组采用常氧培养24 h;B组以1%低氧浓度培养24 h;C组于低氧预处理前用20μmol/L甲氧雌二醇处理24 h;D组于低氧预处理前用50μmol/L缺氧诱导因子1(hypoxia-inducible factor 1,HIF-1)特异的siRNA处理12 h。采用MTT法、生化分析仪及实时荧光定量PCR检测各组BMSCs活力、葡萄糖代谢以及HIF-1αmRNA及葡萄糖转运蛋白1(glucose transporter 1,Glut-1)mRNA的表达。结果 MTT检测示A、B、C、D组吸光度(A)值分别为387.67±58.92、322.50±50.60、297.00±53.00、286.00±41.00,各组间差异无统计学意义(P>0.05)。与A组相比,B组葡萄糖摄取量和乳酸生成量显著增加(P<0.05);C、D组略高于A组,但差异无统计学意义(P>0.05),但显著低于B组,差异有统计学意义(P<0.05);C、D组间比较差异无统计学意义(P>0.05)。与A组相比,B组HIF-1αmRNA和Glut-1 mRNA表达均显著上调(P<0.05);C、D组HIF-1αmRNA和Glut-1 mRNA表达较B组大幅度降低(P<0.05),但仍显著高于A组(P<0.05);C、D组间差异无统计学意义(P>0.05)。结论低氧预处理可上调大鼠BMSCs的葡萄糖摄取和代谢能力,其机制涉及HIF-1 mRNA及其下游基因Glut-1 mRNA的表达上调。     

Outcome effects of different protective hypothermia levels during cardiac arrest in rats

Background: Although hypothermia is widely used to protect the brain during cardiac and neurologic surgery, the optimal level of cooling has not been established. This study examined the protective effect of graded levels of surface cooling on cerebral function in rats after complete global cerebral ischemia.
Methods: Groups of ketamine-anesthetized rats (13 animals in each group) were cooled to cranial temperatures of 34, 30, 27, 24, or 22 °C before circulatory arrest. Also a normothermic (37°C) group was tested. After cooling, an 11-min circulatory arrest was produced by atraumatic chest compression. Circulatory arrest was followed by cardiopulmonary resuscitation and rewarming without postischemic intensive care. On the fifth postinsult day, neurologic outcome was scored on a 50-point neurodeficit scale (NDS O=normal). The percent of ischemic pyramidal neurons in the CAI hippocampal region was also determined.
Results: There were no survivors in the normothermic group. Neurologic recovery was enhanced with 30°C cranial temperature, as compared to outcome in the 34°C group. Further cooling did not change outcome. The neurodeficit scales were significantly lower in all other groups compared to the 34°C group on the fifth postinsult day. The percent of ischemic neurons did not change significantly as a function of cooling, but the lowest count appeared at 27°C.
Conclusion: In this model, moderate (30°C) cooling improved neurologic outcome. There was no additional benefit from more extreme hypothermia.     

大鼠窒息性心跳骤停-心肺复苏改良模型的评价

目的 评价大鼠窒息性心跳骤停-心肺复苏改良模型.方法 雄性SD大鼠15只,2～3月龄,体重350～400 g,麻醉后经口气管插管,机械通气,连续监测心电图、MAP、HR、PETCO2和直肠温度,并维持在正常范围内.静脉注射维库溴铵2 ms/kg后机械通气,5～8 min后再次静脉注射维库溴铵1 mg/kg,1 min后停止机械通气,制备窒息性心跳骤停模型.窒息8 min后,开始药物和标准胸外按压进行心肺复苏(CPR).记录从窒息到心跳骤停的时间、CPR到自主循环恢复的时间、拔管时间,并记录CPR成功及复苏成功后3 d生存的情况.结果 窒息8 min可造成至少4～5 min心跳骤停.CPR开始后2 min内可逆转心跳骤停,使自主循环恢复(MAP>60 mm Hg).从窒息到心跳骤停的时间为(116±12)s,从CPR到自主循环恢复的时间为(42±12)s,拔管时间为(6.9±1.4)h.CPR成功率93%,复苏成功后3 d生存率86%.与窒息前比较,自主循环恢复后即刻、10 min时MAP、HR和PETCO2升高(P<0.05或0.01).结论 大鼠窒息性心跳骤停-心肺复苏改良模型成功率及复苏成功后3 d生存率高,模型稳定,可重复性好,可作为CPR研究的实验动物模型.     

大鼠窒息性心脏停搏复苏后心肌微小RNA表达的变化

目的 探讨大鼠窒息性心脏停搏复苏(CA-CPR)后心肌微小RNA (miRNA)表达的动态变化.方法 清洁级成年雄性SD大鼠64只,体重250 ～ 330 g,采用随机数字表法,将其分为2组(n=32),对照组(C组)和CA-CPR组.采用窒息法建立CA-CPR模型.CA-CPR组于自主循环恢复后3、6、12和24 h(T1-4)时,C组于相应时点取血样,测定血清CK-MB和cTnI浓度,相应时点取心尖部心肌组织,采用Real-Time PCR法检测心肌组织miRNA.以相对于C组心肌miRNA 2倍强度的变化作为CA-CPR组miRNA表达上调或下调的标准.记录大鼠均发生表达变化的miRNA.结果 与C组比较,CA-CPR组各时点血清CK-MB和cTnI浓度升高(P＜0.01);CA-CPR组血清CK-MB浓度T3时达峰值,血清cTnI浓度持续升高(P＜0.05或P＜0.01).自主循环恢复后持续性变化的miRNA有8个,分别为miRNA-1、miRNA-21、miRNA126、miRNA-133a、miRNA-206、miRNA-210、miRNA-320及miRNA-499.miRNA-1各时点表达均上调,T2时最高;miRNA-21各时点表达均下调,T2时最低;miRNA126、miRNA-133a、miRNA-206、miRNA-210和miRNA-499 T1、T2时表达下调,T2时最低,T3、T4时表达上调;miRNA-320T1 ～T3时表达上调,T2时最高,T4时表达下调(P＜0.05或0.01).结论 心脏停搏大鼠复苏后有8个miRNA表达发生变化,且变化方式(上调/下调)、趋势不同,但表达变化方式改变的时点相似.     

纳洛酮或肾上腺素对窒息性心跳骤停大鼠心肺复苏的效果

目的比较纳洛酮或肾上腺素对窒息性心跳骤停大鼠心肺复苏的效果。方法健康SD大鼠24只，体重180～220g，雌雄不拘，制备窒息性心跳骤停模型，随机分成3组（n=8）：对照组在常规心肺复苏（CPR）前静脉注射生理盐水1ml，纳洛酮组和肾上腺素组在常规CPR前分别静脉注射纳洛酮1mg／kg和肾上腺素0．04mg／kg。记录在CPR 10min内自主循环恢复（ROSC）情况。结果对照组、纳洛酮组和肾上腺素组ROSC率分别为12．5％、87．5％和87．5％，纳洛酮组和肾上腺素组ROSC率均高于对照组（P〈0．05），纳洛酮组和肾上腺素组间ROSC率差异无统计学意义（P〉0．05）。结论静脉注射纳洛酮1mg／kg或肾上腺素0．04mg／kg对窒息性心跳骤停大鼠均可有效地进行心肺复苏，且其心肺复苏的早期效果一致。     

Exploring effects of remote ischemic preconditioning in a pig model of hypothermic circulatory arrest

Objectives. During aortic and cardiac surgery, risks for mortality and morbidity are inevitable. Surgical setups involving deep hypothermic circulatory arrest (DHCA) are effective to achieve organ protection against ischemic injury. The aim of this study was to identify humoural factors mediating additive protective effects of remote ischemic preconditioning (RIPC) in a porcine model of DHCA. Design. Twenty-two pigs were randomized into the RIPC group (n?=?11) and the control group (n?=?11). The RIPC group underwent four 5-minute hind limb ischemia-reperfusion cycles prior to cardiopulmonary bypass and DHCA. All animals underwent identical surgical procedures including 60?min DHCA at 18?°C. Blood samples were collected from vena cava and sagittal sinus at several time points. After the 8-hour follow-up period, the brain, heart, and kidney tissue samples were collected for tissue analyses. Results. Serum levels of brain damage marker S100B recovered faster in the RIPC group, after 4?hours of the arrest, (p?Conclusions. The faster recovery of S100B, lower systemic lactate levels and favourable regional antioxidant response suggest possible neuronal cellular and mitochondrial protection by RIPC, whereas better cardiac index underlines functional effects of RIPC. The exact humoural factor remains unclear.     

气管夹闭窒息法家兔心脏骤停模型的研究

目的　用气管夹闭窒息法建立一种稳定的心肺复苏动物模型。方法　家兔呼气末夹闭气管窒息法致心脏停搏 ,夹管后 8min行标准心肺复苏 5min ,观察窒息和复苏期间的MAP与心电图变化。结果　气管夹闭前MAP为 (111± 7)mmHg(1mmHg =0 .13 3kPa) ,夹闭后MAP明显下降时间为 (172± 2 0 )s ,降至 5 0mmHg时间为 (2 2 8± 3 3 )s ,5min时为 (2 7± 12 )mmHg ,7min时为 (8± 4)mmHg ,MAP变化与心电图变化一致 ;自主循环恢复 16例 ,未恢复 2例 ,心肺复苏成功率为 89%。结论　该模型具有稳定、简单、重复性好的特点 ,能够满足心肺复苏实验研究需要。     

氯胺酮联合亚低温对窒息性心跳骤停大鼠复苏后脑缺血再灌注损伤的影响

目的 探讨氯胺酮联合亚低温对窒息性心跳骤停大鼠复苏后脑缺血再灌注损伤的影响.方法 健康Wistar大鼠50只,4.0～4.5个月,雌雄各半,体重410～510 g,随机分为5组(n=10):假手术组(S组)仅经动、静脉穿刺置管;窒息性心跳骤停组(ACA组)制备窒息性脑缺血模型;氯胺酮组(K组)窒息前5 min腹腔注射氯胺酮100 mg/kg;亚低温组(MH组):窒息开始后维持直肠温30～35℃;氯胺酮+亚低温组(K+MH组):窒息前5 min腹腔注射氯胺酮100 mg/kg,窒息开始后维持直肠温30～35 ℃.成功复苏后,取脑组织,测定脑含水量和海马神经元p-caspase-3的表达水平.结果 与S组比较,ACA组和K组脑含水量升高,p-caspase-3表达上调,MH组和K+MH组p-caspase-3表达上调(P＜0.01),脑含水量差异无统计学意义(P＞0.05);与ACA组比较,MH组和K+MH组脑含水量降低,p-caspase-3表达下调,K组p-caspase-3表达下调(P＜0.01),脑含水量差异无统计学意义(P＞0.05);与K组比较,K+MH组脑含水量降低,p-caspase-3表达下凋,MH组脑含水量降低(P＜0.01),p-caspase-3表达差异无统计学意义(P＞0.05);与MH组比较,K+MH组p-caspase-3表达下调(P＜0.01),脑含水量差异无统计学意义(P＞0.05).结论 氯胺酮联合亚低温可减轻窒息性心跳骤停大鼠复苏后的脑缺血再灌注损伤,该效应较两者单独应用时增强.