大鼠脑缺血后高血糖对血脑屏障通透性的影响

THE EFFCECT OF HYPERGLYCEMIA ON BLOOD BRAIN BARRIER AFTER PROFOUND TEMPORARY CEREBRAL ISCHEMIA IN RATS

采用３Ｈ标记的α－氨基异丁酸（３Ｈ－ＡＩＢ）做为血脑屏障（ＢＢＢ）通透性指示剂，定量观察了高血糖大鼠脑缺血后ＢＢＢ的变化。结果发现，在大鼠４血管阻断脑缺血２０ｍｉｎ，高血糖组ＢＢＢ通透性明显高于正常血糖组及非脑缺血对照组；正常血糖组与对照组间无明显差异。提示高血糖能够加重ＢＢＢ损害，ＢＢＢ的损害可能是高血糖加重脑缺血性损害及脑水肿的重要病理生理机制之一。

Clinical and experimental date indicate that hyperglycemia can aggravate the consequences of cerebral ischemia.Because breakdown of blood brain barrier(BBB) play an importment role in cerebral ischemia, using ( 3H)α aminoisobutyric acid( 3H AIB) as a passive permeability marker, we quantitatively studied the permeability of BBB to 3H AIB in hyperglycemic rats undergoing 20 minutes of four vessel occlusion followed by 12 minutes of postischemic recirculation.The result showed that the permeability of BBB to 3H AIB was significantly increased in hyperglycemic rats compared with normoglycemic and control group. This finding indicates that hyperglycemia significantly worsens the degree of BBB injury.Postischemic BBB disruption may play an importment role in the pathogenesis of increased brain damage associated with hyperglycemia.