【作者】 刘磊；

【导师】 潘进社；

【作者基本信息】 河北医科大学 ， 外科学， 2008， 硕士

【摘要】 目的:临床上各种原因引起的骨骼肌缺血十分常见。缺血组织恢复血液灌注后,部分组织细胞功能代谢障碍及结构破坏反而更重,这种血液再灌注使缺血性损伤进一步加重的现象称为缺血-再灌注损伤(ischemia-reperfusion injury,I/R)。而有学者发现短暂重复缺血,间断再灌注的方法能够提高组织缺血耐受性,这种方法称为缺血预处理(ischemicpreconditioning IPC)。IPC提高组织对缺血的耐受性,减轻组织缺血再灌注损伤的作用已经在不同实验动物的不同器官、组织中得到证实。但是缺血预处理时间和循环次数并无统一标准,不同的预处理方法对骨骼肌缺血再灌注损伤的保护作用是否有差别、何种缺血预处理方法能对骨骼肌缺血再灌注损伤的保护作用达到最大程度目前也尚无统一意见。本研究模拟临床气囊止血带的应用方法,建立兔后肢缺血再灌注损伤模型,观察不同的缺血预处理方法(缺血间隔时间、间隔次数)对骨骼肌缺血再灌注损伤的保护作用是否存在差别,以期发现何种预处理方法能使IPC保护作用最强。方法:选择体重2.2-2.7kg,新西兰白兔56只,随机分为I/R、A、B、C、D、E、F组7组,每组8只。I/R组不行预处理。A组:进行2次5min间断缺血,中间间隔2次5min间断再灌流预处理,随后持续缺血4h,最后松止血带恢复肢体血流。B组:进行3次5min间断缺血,中间间隔3次5min间断再灌流预处理,随后持续缺血4h,最后松止血带恢复肢体血流。C组:进行4次5min间断缺血,中间间隔4次5min间断再灌流预处理,随后持续缺血4h,最后松止血带恢复肢体血流。D组:进行2次10min间断缺血,中间间隔2次10min间断再灌流预处理,随后持续缺血4h,最后松止血带恢复肢体血流。E组:进行3次10min间断缺血,中间间隔3次10min间断再灌流预处理,随后持续缺血4h,最后松止血带恢复肢体血流。F组:进行4次10min间断缺血,中间间隔4次10min间断再灌流预处理,随后持续缺血4h,最后松止血带恢复肢体血流。再用气囊止血带阻断兔后肢血流4h,造成骨骼肌缺血再灌注损伤模型。测定再灌注2h后兔血清中肌酸磷酸肌酶(CPK)和天门冬氨酸氨基转移酶(AST)含量,肌肉干湿比。使用SPSS11.0统计软件包进行统计分析,各组数据均进行正态检验及方差齐性检验,以均数±标准差表示,不同预缺血时间、循环次数对骨骼肌缺血再灌注损伤的影响数据采用方差分析(ANOVA),组间比较采用SNK-q检验。结果:1、血清中CPK、AST含量的比较I/R组和行预处理各组再灌注2h后动物血清中CPK和AST均有不同程度的升高。I/R组再灌注2h后动物血清中CPK含量为9267.2±671.2,AST含量为246.7±18.2,较其它各组均高,差异有显著性意义(P＜0.01)。E组再灌注2h后动物血清中CPK含量为4621.6±297.6,AST含量为117.6±8.6,较其它各组均低,差异有显著性意义(P＜0.05)。相同的预缺血时间下,再灌注后2h,B组CPK(8414.5±634.4),AST(156.8±11.3)含量较A组、C组低,E组CPK(4621.6±297.6)和AST(117.6±8.6)含量较D组、F组低,差异有显著性意义(P＜0.05)。相同的预缺血循环次数下,再灌注后2h,D组CPK和AST含量小于A组,E组小于B组,F组小于C组,差异有显著性意义(P＜0.05)。B组与F组,C组与D组相比差异无显著性(P＞0.05)。(表1、3、4)2、肌肉干湿比的比较再灌注后2h,与对照组相比各实验组肌肉均有不同程度的水肿(P＜0.01)。I/R组再灌注2h后肌肉干湿比为0.1630±0.016,较其它各实验组均低,肌肉水肿程度最重,差异有显著性意义(P＜0.01)。E组再灌注2h后肌肉干湿比为0.2780±0.028,较其它各实验组均高,肌肉水肿程度最轻,差异有显著性意义(P＜0.05)。相同的预缺血时间下,再灌注后2h,B组肌肉干湿比较A组、C组高,E组肌肉干湿比较D组、F组高,差异有显著性意义(P＜0.05)。相同的预缺血循环次数下,再灌注后2h,D组肌肉干湿比大于A组,E组大于B组,F组大于C组,差异有显著性意义(P＜0.05)。B组与F组,C组与D组相比差异无显著性(P＞0.05)。结论:1、IPC对骨骼肌缺血再灌注损伤具有一定的保护作用。2、缺血预处理5 min对肌肉坏死即有保护作用,在相同的循环次数下预缺血10 min效果较5 min者好。缺血预处理2次循环对肌肉坏死即有保护作用,3次循环保护作用达高峰,而4次循环保护作用又相对减弱,但好于2次循环的保护效应。缺血预处理5 min,4次循环与预处理10 min,2次循环对骨骼肌保护作用无差别,缺血预处理5 min,3次循环与预处理10 min,4次循环对骨骼肌保护作用无差别。3、IPC总的保护作用呈先逐渐增强再逐渐减弱的趋势。预处理10 min,循环3次对骨骼肌缺血再灌注损伤保护作用最强。更多还原

【Abstract】 Objection:The ischemic injuries of skeletal muscle are common diseases in clinic.Ischemia-reperfusion injury(I/R)is a pathological phenomenon that while ischemic tissues were reflowed, dysbolismus and disorganization of histiocyte will get worse. Prevention and cure of ischemia-reperfusion injury had been a focus.Ischemic preconditioning(IPC)is a method that short term ischemia and reperfusion interrupted may improve the tolerance of skeletal muscle.Functions of IPC had been already improved through different animal experiments.However there have no consistent standard of IPC treatment.Whether or not protective effects of different IPC treatments are different? Which IPC treatment would protect skeletal muscle hardest? There is no a consistent opinion about those questions at present. Based on above-mentioned questions,rabbits were made I/R -like models in this experiment to study protective effects of different Ischemic preconditioning treatments against Ischemic-Reperfusion injury.Expect to find which IPC treatment would protect skeletal muscle hardest.Methods:Fifty-six healthy rabbits(2.2-2.7 kg weight)were used in the experiment.The animals were divided randomly into seven groups with eight rabbits in each:an I/R group,six IPC groups(an A group,a B group,a C group,a D group,an E group and an F group).The blood flows of the rabbits limbs were stopped with a special pneumatic tourniquet.The I/R group underwent a 4 hour ischemia directly.The IPC groups were subjected to 4 hour ischemia directly after different ischemic preconditioning treatments(5 or 10 minutes of ischemia and 5 or 10 minutes of reperfusion respectively,for 2-4 cycles),an The contents of CPK,AST in the serum dry to wet ratio of skeletal muscle after 4 hour reperfusion were measured to observe protective effects of different ischemic preconditioning treatments.All the experimental data was analyzed by SPSS 11.0.Results:1 CPK、AST in blood serum.The contents of CPK, AST in the serum of all groups at 2 hours after reperfusion are higher than normal.At 2 hours after reperfusion,CPK(9267.2±671.2),AST(246.7±18.2)in I/R group was significantly superior to that of other groups(P＜0.01).CPK(4621.6±297.6), AST(117.6±8.6)in E group was significantly inferior to that of other groups(P＜0.05).In groups with same IPC duration CPK(8414.5±634.4),AST(156.8±11.3)in B group was significantly inferior to that of A and C group(P＜0.05). CPK(4621.6±297.6),AST(117.6±8.6)in E group was significantly inferior to that of D and F group(P＜0.05).In groups with same IPC cycles,at 2 hours after reperfusion,CPK AST in D group was significantly inferior to that of A group(P＜0.05),CPK AST in F group was significantly inferior to that of C group(P＜0.05).There were no significant difference between B group and F group,C group and D group(P＞0.05).(Table 1、3、4)2 Dry to wet ratio(D/W)of skeletal muscle.At 2 hours after reperfusion,D/W in test group was significantly inferior to that of control groups(P＜0.01).D/W in I/R group(0.1630±0.016) was significantly inferior to that of other test groups(P＜0.01). D/W in E group(0.2780±0.028)was significantly superior to that of other test groups(P＜0.05).In groups with same IPC duration,D/W in B group was significantly superior to that of A and C group(P＜0.05).D/W in E group was significantly superior to that of D and F group(P＜0.05).In groups with same IPC cycles,at 2 hours after reperfusion,D/W in D group was significantly superior to that of A group(P＜0.05),D/W in F group was significantly superior to that of C group(P＜0.05).There were no significant difference between B group and F group,C group and D group(P＞0.05).(Table 2、5)Conclusions:1 IPC may improve the tolerance of skeletal muscle to I/R,bu it is not infinite.2 Five minutes of ischemic preconditioning(IPC5)could protect skeletal muscle of ischemia against necrosis.In same IPC cycles the effects of IPC10 were significantly superior to that of IPC5.Two cycles of ischemic preconditioning could protect skeletal muscle of ischemia against necrosis.Three cycles of IPC is optimal,and protective effects of IPC with four cycles go down but it is better than that of IP5.There were no significant difference between 5 minutes of IPC,4 cycles and 10 minutes of IPC,2 cycles.There were no significant difference between 5 minutes of IPC,3cycles and 10 minutes of IPC,4 cycles.3 The trend of protective effect of IPC on ischemia-reperfusion injury of the muscle in rabbit’s first rise to the peak and then go down,10 minutes of IPC,3cycles is optimal.更多还原