Effect of quercetin pretreatment on permeability of blood-brain barrier in a rat model of global cere-bral ischemia-reperfusion / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of quercetin pretreatment on the permeability of blood-brain barrier in a rat model of global cerebral ischemia-reperfusion ( I∕R). Methods Sixty-three clean-grade healthy male Sprague-Dawley rats, weighing 300-350 g, aged 4-5 months, were divided into 3 groups (n＝21 each) using a random number table method: sham operation group ( group S), group I∕R and quercetin pretreatment group ( group Q). Global cerebral I∕R was induced by occlusion of bilateral common carotid arteries combined with hypotension ( mean arterial pressure was maintained at 35-45 mmHg) in chloral hydrate-anesthetized rats. Quercetin 25 μmol∕kg was injected intraperitoneally twice a day for 3 consecutive days starting from 3 days before establishment of the model in group Q, while the e-qual volume of normal saline was given instead at the corresponding time points in group S and group I∕R, respectively. The animals were sacrificed at 24 h of reperfusion and brains were removed to determine the brain water content, Evans blue ( EB) content and expression of occludin protein in cerebral cortex ( by Western blot) and to observe the ultrastructure of blood-brain barrier. Results Compared with group S, the brain water content and EB content were significantly increased, the expression of occludin protein was down-regulated (P＜0. 05), and the injury to ultrastructure of blood-brain barrier was accentuated in I∕R and Q groups. Compared with group I∕R, the brain water content and EB content were significantly de-creased, the expression of occludin protein was up-regulated (P＜0. 05), and the injury to ultrastructure of blood-brain barrier was significantly attenuated in group Q. Conclusion Quercetin pretreatment can de-crease the permeability of blood-brain barrier and attenuate brain edema, and the mechanism may be related to up-regulated expression of occludin protein in a rat model of global cerebral I∕R.