Effect of lipoxin A4 on permeability of blood-brain barrier after focal cerebral ischemia-reperfusion in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of lipoxin A4 ( LXA4 ) on the permeability of blood-brain barrier (BBB) after focal cerebral ischemia-repeffnsion (I/R) in rats. Methods Fifty-four adult male SD rats weighing 200-250 g were randomly divided into 3 groups ( n = 18 each): group Ⅰ sham operation (group S); group Ⅱ focal cerebral I/R ( group I/R) and group Ⅲ LXA4 ( group L). Focal cerebral I/R was produced by middle cerebral artery occlusion (MCAO) with a 4-0 nylon thread with rounded tip inserted into right internal jugular vein and threaded cranially in group Ⅱ and Ⅲ . In group Ⅲ LXA4 100 ng was injected into right lateral ventricle of the brain after MCA was successfully occluded. MCAO was maintained for 2 h. The neurological deficit was evaluated and scored (0 = no deficit, 5 = death) at 24 h of reperfusion. 2% Evans blue 4 ml/kg was injected via femoral vein at 1 h before the animals were sacrificed. The animals were killed and their brains were immediately removed for determination of brain water content, Evans blue content and expression of matrix metalloproteinase-9 (MMP-9)in the ischemic cortex. Results The neurologic deficit scores, the brain water and Evans blue content and MMP-9 protein expression in the cortex were significantly higher in I/R group than in S group. The cerebral I/R-induced changes were significantly attenuated in LXA4 group. Conclusion LXA4 can protect blood-brain barrier against cerebral I/R injury by inhibiting MMP-9 protein expression in the brain tissue.