老龄大鼠脑缺血再灌注血脑屏障损伤的变化及意义

目的研究老龄大鼠脑缺血再灌注（I／R）血脑屏障（BBB）损伤特点。方法采用大脑中动脉栓塞法复制局灶性脑缺血模型，随机分组，观察脑组织含水量、病理变化、免疫球蛋白（IgG）。结果随着再灌注时间的延长，BBB损伤逐渐加重，含水量增加和IgG漏出以I／R24h、3d显著；模型组含水量（I／R 12h～6d）较假手术组升高；青年模型（I／R12h～6d）和老龄模型（I／R 6h～6d）IgG漏出分别较青年和老龄脑缺血3h组增加；老龄模型组（I／R 12h～I／R6d）IgG的漏出高于同时间青年模型组。结论脑水肿和BBB损伤随着再灌注时间的延长而加重，IgG漏出老年较青年明显，血脑屏障的增龄变化可能是其机制之一。

The significance of the changes in blood-brain barrier during cerebal ischemia/reperfusion in the aged rats

Objective To study the changes of blood-brain barrier (BBB) during cerebal ischemia/reperfusion in the aged rats. Methods Duplicated focal cerebal ischemia model of MCAO in SD rats,divided into groups in random. The pathologic changes and the changes of the water content of brain constitution and immunoglobulin G (IgG) were obsvered. Results Along with the prolonging of ischemia reperfusion time,the BBB lesion became more serious gradually and peaked at I/R 24h and 3d with the increase of the water content of brain constitution and IgG leakage. The water content of brain constitution of model groups was higher than that of sham-operated groups. The content of IgG leakage of the young model groups(I/R 12h - 6d)and the aged model groups(I/R 6h-6d) was lower respectively than that of the young ischemia 3h group and aged ischemia 3h group. The content of IgG leakage of the aged model groups was obviously higher than that of the young model groups. Conclusion The ischemia brain edema and BBB lesion were correlated to the ischemia reperfusion time while the IgG leakage of the aged ones were more serious than that of the youngs. The BBB changes with age might be one of the mechanisms.