MK801对大鼠肢体缺血/再灌注致脑组织发生细胞凋亡的影响

EFFECT OF MK801 ON APOPTOSIS IN THE DEVELOPMENT OF BRAIN INJURY AFTER HIND LIMBS ISCHEMIA/REPERFUSION IN RATS

目的:探讨肢体缺血/再灌注(LI/R)后,脑组织损伤的发生及MK801的影响。方法:采用文献[4]方法复制大鼠肢体缺血再灌损伤模型,给予MK801处理,观察各组动物脑组织中丙二醛(MDA)含量的变化,TUNEL法检测细胞凋亡情况,免疫组化和Western印迹法检测凋亡相关因子Bcl-2、细胞色素C(cytoC)、Caspase-3表达的变化。结果:大鼠LI/R后,脑组织中MDA含量升高,中脑红核区有大量胞浆呈棕色的Bcl-2、cytoC、Caspase-3蛋白阳性细胞分布,且细胞凋亡明显增加。MK801干预组与LI/R组相比MDA含量显著下降,Bcl-2、cytoC、Caspase-3蛋白表达降低,差异显著,且细胞凋亡相应降低。结论:凋亡相关因素Bcl-2、cytoC、Caspase-3变化介导的细胞凋亡参与大鼠LI/R后所致脑损伤过程。减弱谷氨酸兴奋性毒性作用及氧自由基损伤、影响凋亡相关基因表达可能是MK801脑保护的机制之一。

Aim：To evaluate development of brain injury after hind limbs ischemia/reperfusion（LI/R）in rats,and the effect of MK801 on the brain injury following LI/R.Methods：The limbs ischemia/reperfusion model was established in rats.The MDA contents were evaluated in each group,apoptotic cells were detected with TUNEL,the expression of apoptosis-associated protein,such as bcl-2,cytoC and caspase-3 were determined with immunohistochemistry and Western-blot.Results：The contents of MDA in brain tissue increased significantly following LI/R.The expression of bcl-2,cytoC,Caspase-3 was increased than those in the control group（P〈0.01）following LI/R significantly.The expression of Caspase-3 was increased 24 h after the onset of reperfusion.The expression of Caspase-3,bcl-2 gene was quite obvious in the midbrain red nucleus region.MK801 inhibited the expression of bcl-2,cytoC,Caspase-3 obviously.Conclusion：The excessive apoptosis and apoptosis-associated factors could play an important role in the brain injury following LI/R in rat,MK801 might decrease the production of free radical and the excite toxicity of glutamate,inhibit the expression of apoptosis associated protein and reduce the occurrence of apoptosis.