缺血预处理对骨骼肌缺血再灌注损伤的保护机制及其与腺苷关系研究

目的 :探讨骨骼肌缺血预处理保护作用机制及其腺苷的关系。方法 :采用兔右后肢缺血模型 ,将 2 8只兔随机分为 4组 (n =7) ,对照组 :持续缺血 4h ,再灌注 1h ;预处理组 :缺血 5min ,再灌注 5min ,重复 3次后 ,持续缺血 4h再灌注1h。腺苷治疗组 :于缺血再灌注前经股动脉注入 0 5mg腺苷。腺苷受体拮抗剂 8-PT处理组 :在 3次循环IPC处理前 ,经股动脉注入 3 0mg 8-PT ,再缺血 4h ,再灌注 1h。通过高效液相色谱法测定处理前、缺血 4h ,再灌注 10min、3 0min及6 0min时血浆腺苷浓度变化。通过血浆CPK、MDA及骨骼肌99mTcMDP吸收量的测定判断骨骼肌损伤程度。结果 :预处理组、腺苷组及 8-PT组 ,在缺血 4h和再灌注 1h期间血浆腺苷浓度明显升高 (P <0 0 1) ,再灌注 10min时达到高峰 ,并随再灌注时间延长而逐渐降低。与对照组相比 ,预处理组和腺苷组血浆CPK、MDA及骨骼肌99mTcMDP吸收量显著降低 (P <0 0 1)。结论 :腺苷参与了缺血预处理对骨骼肌的保护作用 ,腺苷受体拮抗可阻断缺血预处理对骨骼肌的保护作用。腺苷释放和腺苷受体激活在骨骼肌缺血预处理中起重要作用。

A Study on Relationship between Plasma Adenosine Level and Protective Mechanism of Ishemic Preconditioning against Skeletal Muscle Ischemia Reperfusion Injury

Objective:To study the protective mechanism of ischemic preconditioning against skeletal muscle ischemia injury and the effect of adenosine in rabbits.Methods:ischemic preconditioning model of the hindlimb was set up,and 28 rabbits were randomly divided into four groups reperfusion.Ischemic preconditioning group,endered 4 hrs ischemia and 1h reperfusion after 3 cycles of 5 min,ischemia reperfusion ischemic preconditioning.Adenosine treatmia group,injection of adenosine in femoral artery befor ischemia and reperfusion.Adenosine receptor antagonist 8-PT group,treatment with adenosine receptor antagonist 8-PT before ischemic preconditioning.Adenosine contents in blood were determined by highperfomance liquid chromatography during ischemia,and reperfusion.The degree of muscle damage was measured by changes of MDA,CPK in plasma and the uptake of 99m TcMDP in skeletal muscle Result:Blood adenosine contents in ischemic preconditioning group,adenosine group and 8-PT group were significantly higher in comparison with control group,it reached the highest point when reperfusion 10 min,and reduced slowly after 10 min of reperfusion,and the uptake of 99m TcMDP in muscle were significantly lower in ischemic preconditioning group and adenosine treatment group than that in control group.Conclusion:Adenosine involve in the protective effect of ischemic preconditiong,and the protective effect of ischemic preconditiong might be blocked by adenodine receptor antagonist 8-PT.Adenosine and adenosine receptors play an important role in skeletal muscle ischemic preconditioning.