| 摘要: |
| 目的:观察缺血后处理与控制性低压灌注对大鼠脊髓缺血-再灌注损伤的影响。方法:雄性SD大鼠309只,随机分为3组(n=103):对照组(Control组)、后处理组(Post-con组)和低压灌注组(LR组)。2F Fogarty球囊导管阻断胸主动脉9 min合并体循环低压40 mmHg(1 mmHg=0.133 kPa)诱导大鼠脊髓缺血。 再灌注期,Control组以平均动脉压(MAP)100 mmHg迅速回灌； Post-con组进行3次30 s再灌/30 s阻断的操作；LR组MAP维持40 mmHg 3 min再升至100 mmHg。监测再灌30 min内脊髓相对血流量(rSCBF)；测定再灌1、4、12、24 h腰骶部脊髓组织超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和髓过氧化物酶(MPO)的活性,及丙二醛(MDA)含量；评定大鼠后肢神经功能,观察脊髓腰段的病理改变。 结果:后处理和低压灌注可改善再灌早期的高流量状态。与Control组比较,Post-con组于再灌1、4 h SOD、CAT活性上调,24 h内MDA含量降低,MPO活性下降(P<0.01)。LR组MDA含量虽降低(P<0.05),但SOD、CAT活性无变化；MPO活性于再灌1、4 h达峰值,后逐渐下降。Post-con及LR组再灌注24 h内神经功能皆明显好转,但LR组的神经行为学评分低于Post-con组。脊髓病理改变与行为学结果类似。 结论:缺血后处理与控制性低压灌注皆可减轻大鼠脊髓缺血-再灌注损伤,但由于缺血后处理可提高再灌注期内源性抗氧化酶活性、减少中性粒细胞堆积而具有更强的脊髓保护作用。 |
| 关键词: 缺血后处理 低压力 再灌注 脊髓 缺血-再灌注损伤 |
| DOI：10.3724/SP.J.1008.2008.01341 |
| 投稿时间：2008-01-07修订日期：2008-07-09 |
| 基金项目: |
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| Effects of ischemic postconditioning and controlled low-pressure reperfusion on ischemia and reperfusion-induced spinal cord injury in rats |
| WANG Li-ping1,2,LI Wen-xian1* |
| (1.Department of Anesthesiology,Changhai Hospital,Second Military Medical University,Shanghai 200433,China;2.Department of Anesthesiology,Fuzhou General Hospital,PLA Nanjing Military Area Command,Fuzhou 350025) |
| Abstract: |
| Objective:To investigate the effects of ischemic postconditioning and controlled low-pressure reperfusion on ischemia and reperfusion-induced spinal cord injury.Methods: Spinal cord ischemia was induced by occlusion of the descending thoracic aorta combined with maintaining systemic hypotension (40 mmHg,1 mmHg=0.133 kPa) in rats.Rats were randomly divided into three groups (n=103),namely,control group,postconditioning group (Post-con group) and low-pressure reperfusion group (LR group).Rats in control group underwent an abrupt increase to 100 mmHg in mean arterial pressure (MAP) after reperfusion.Those in the Post-con group underwent 3 cycles of 30-second reperfusion and 30-second occlusion after 30-second full reperfusion with MAP of 100 mmHg.The MAP maintained 40 mmHg for the initial 3 min of reperfusion in the animals of the LR group,then increased to 100 mmHg.The relative spinal cord blood flow (rSCBF) was monitored simultaneously during the ischemia and 30 min after reperfusion.The activities of superoxide dismutase (SOD),catalase (CAT) and myeloperoxidase (MPO) and malondialdehyde (MDA) content in lumbar spinal cord tissue were measured at 1,4,12 and 24 h after reperfusion,and the neurologic function of hind-limb was also evaluated at the same time.The samples of lumbar spinal cord were collected in all groups at the end of observation for histological examination.Results: Postconditioning and low-pressure reperfusion both improved the hyperperfusion after reperfusion.In Post-con group the activities of SOD and CAT was markedly increased 1 and 4 h after reperfusion (P<0.01) compared with control group,and no marked increase in MDA and MPO was observed.The MDA in the spinal tissue of LR group was significantly lower than that of the control group (P<0.01),but no significant increases were observed in the activities of SOD and CAT.The MPO activity in LR group peaked from the 1st to 4th hour of reperfusion and then gradually reduced.Postconditioning and low-pressure reperfusion both improved the neurologic function during reperfusion,but behavioral scores of animals in LR group were lower than that in the Post-con group.The pathological results had a similar pattern to the behavioral scores in all 3 groups 24 h after reperfusion.Conclusion: Ischemic postconditioning and controlled low-pressure reperfusion can both attenuate ischemia and reperfusion injury in spinal cord,and the neuroprotection of ischemic postconditioning is superior to controlled low-pressure reperfusion,probably because postconditioning can enhance activities of antioxidant enzymes and decrease neutrophil accumulation. |
| Key words: ischemic postconditioning low pressure reperfusion spinal cord ischemia-reperfusion injury |
