P-选择素和L-选择素在大鼠脑缺血/再灌注损伤中表达的实验研究

目的研究P-选择素和L-选择素在大鼠局灶性脑缺血／再灌注后的表达规律，探讨它们在脑缺血／再灌注损伤中的作用。方法72只雄性SD大鼠随机分为假手术组、P-选择素组、L-选择素组和持续缺血组，采用尼龙线栓法建立大鼠局灶性脑缺血／再灌注模型，用免疫组化方法检测脑组织缺血／再灌注不同时间点P-选择素和L-选择素的表达。结果假手术组未见P-选择素和L-选择素的表达，P-选择素在脑缺血／再灌注后3h出现少量表达，12h达高峰，48h仍有表达；L-选择素在脑缺血／再灌注后2h出现少量表达，6h达高峰，24h仍有表达。结论大鼠局灶性脑缺血／再灌注损伤中，P-选择素和L-选择素的表达明显上调，两者介导了白细胞、脑微血管内皮细胞的黏附，参与了脑缺血／再灌注损伤的病理过程。

Experimental studies of the expression of P- selectin and L - selectin in the rats with focal cerebral ischemia - reperfusion injury

Objective To evaluate the expression of P-selectin and L-selectin in the rats with focal cerebral ischemia-reperfusion and study the effect of P-selectin and L-selectin on cerebral ischemia-reperfusion injury.Methods 72 male SD rats were randomly divided into the sham operated group and cerebral ischemia 2 h with reperfusion 2,3,4,6,12,24,48 h group.The focal cerebral ischemia-reperfusion models of middle cerebral artery occlusion(MCAO) were made by inserting nylon surgical thread through the internal carotid artery(ICA) into the anterior cerebral artery(ACA).The expression of P-selectin and L-selectin were evaluated by immunohistochemical method at different reperfusion time points.Results P-selectin and L-selectin could not be detected in sham operated control group.P-selectin was detected as early as 3 h after reperfusion and peaked at 12 h and still could be detected at 48 h.Lselectin was detected as early as 2 h after reperfusion and peaked at 6h after reperfusion and still could be detected at 24 h.Conclusions The upregulated expression of P-selectin and L-selectin in the rats with focal cerebral ischemia-reperfusion suggests that P-selectin and L-selectin enhance leukocytes' adhesion to cerebral microvascular endothelial cells,and involve in the inflammatory injury of cerebral ischemia-reperfusion.