脂氧化酶参与脑缺血预处理机制的研究

摘要

目的 探讨缺血预处理(IPC)对小鼠缺血再灌注脑损伤的保护作用中12/15-脂氧化酶(12/15-LOX)途径的作用及机制.方法 健康雄性C57BL/6小鼠随机分成假手术组、大脑中动脉区局灶性脑缺血(MCAO)组、IPC假手术-MCAO组及IPC-MCAO 4组.所有组别小鼠分别进行相应处理后处死取脑组织,通过2,3,5-氯化三苯四唑(5-triphenyl tetrazolium chloride, TTC)染色法评估小鼠脑梗死面积;应用免疫印迹法(Western blot)测定12/15-LOX蛋白表达,酶联免疫吸附测定法(enzyme-linked immunosorbent assay, ELISA)检测12/15-LOX产物15-羟二十四烷四烯酸(15-HETE)的表达.结果IPC-MCAO组梗死体积百分比为[(22.49±6.82)%,n=7]较MCAO组[(32.91±6.25)%,n=7]及IPC假手术-MCAO组[(31.97±5.53)%, n=7]梗死体积明显缩小(P<0.05);并且IPC-MCAO组小鼠脑组织中12/15-LOX的蛋白表达及其调控产物15-HETE较MCAO组和IPC假手术-MCAO组也明显降低(P<0.05),而以上各指标在IPC假手术-MCAO组和MCAO组中均无统计学差异(P>0.05).结论 缺血预处理对小鼠缺血再灌注损伤脑的保护作用与其对12/15-LOX及其调控产物的抑制作用相关.%Objective The experiment aimed to confirm the protective effects against ischemia-reperfusion injury and investigate its potential mechanism in 12/15-lipoxygenase (12/15-LOX) pathway.Methods Male C57BL/6 mice were randomly distributed into 4 groups: Sham-operated group, MCAO group, Sham-IPC-operated-MCAO group and IPC-MCAO group.After the operation,the mice were sacrificed for brain disection.The cerebral infarction volume was measured by 2, 3, 5-triphenyltetrazolium chloride (TTC)-staining, while the protein expression of 12/15-LOX was measured by Western blot analysis, and the product of 12/15-LOX--15-HETE, was measured by Elisa.Results In contrast with the mice of MCAO group[(32.91±6.25)%, n=7] and Sham-IPC-operated-MCAO group[(31.97±5.53)%, n=7], the infarct volume of IPC-MCAO group[(22.49±6.82)%, n=7]were significantly reduced(P<0.05), and the expression of 12/15-LOX and its product, 15-HETE were also significantly reduced(P<0.05).And there was no significant difference between the cases of MCAO group and sham-IPC-operation-MCAO group (P>0.05).Conclusion The results suggested that the cerebral protective effects of pretreatment with ischemic preconditioning was related to inhibition of 12/15-LOX.