Changes of expression of P-glycoprotein after cerebral ischemia reperfusion in rats / 重庆医学

ABSTRACT

Objective To observe the changes of the expression of P-glycoprotein(P-gp) after 90 min focal cerebral ischemia reperfusion in rats.Methods The model of.focal cerebral ischemia induced by blocking middle cerebral artery was made by using an intraluminal filament technique.A total of 26 adult SD male rats was used for experiment.One of them was applied for the 2,3,5-triphenyl tetrazolium chloride(TTC) staining to detect whether the focal cerebral ischemia model was successfully made,and the remaining rats were randomly divided into control group(n =5),sham operation group(n =5),and cerebral ischemia reperfusion for 1,3,7 d group(n=5).The immunohistochemistry single staining was used to observe the changes of P-gp in the normal and repefued ischemial brain tissue.The immunofluorescence double staining was used to observe the expression of P-gp in the normal and repefued ischemial brain tissue with Mdr-1 antibody,Neun antibody(marker of the neuron),GFAP antibody(marker of the astrocytes),and CD31 antibody(marker of capillary endothelium).Meanwhile the changes of P-gp in ischemic cerebral cortex and striatum capillary were analyzed by using real-time quantitative PCR technique.Results In control group,P-gp was only located in cerebral microvascular endothelial cells,while in cerebral ischemia reperfusion group,it also could be detected in some neurons and astrocytes.After cerebral ischemia reperfusion,the mRNA expression of P-gp in cerebral cortex was decreased on day 1,significantly increased on day 3,and then decreased on day 7.There was significantly statistical difference of the mRNA expression of P-gp cortex in cerebral ischemia reperfusion for 1,3,7 d group compared with control group and sham group(P＜0.05).After cerebral ischemia reperfusion,the mRNA expression of P-gp in cerebral striatum was increased on day 1,day 3and day 7,especially on day 1 and day 7,and the difference in cerebral ischemia reperfusion group was statistically significant compared with the other two groups (P＜0.05).Conclusion P-gp can only be expressed in cerebral microvascular endothelial cells in normal rats,while it can also be expressed in neurons and astrocytes in rats after the brain's subjection to ischemia reperfusion,and it showed different tendencies between cortex and striatum,which may be regarded as one of the self-protection mechanisms in brain tissue.