高压氧预适应对大鼠大脑中动脉闭塞后骨桥蛋白表达的影响

Effect of hyperbaric oxygen preconditioning on osteopontin expression in MCAO rats

目的观察高压氧预适应(hyperbaric oxygen preconditioning,HBOP)对大鼠大脑中动脉闭塞(middle cerebral artery occlusion,MCAO)后的神经保护作用并初步探讨其对骨桥蛋白(osteopontin,OPN)表达的影响。方法雄性SD大鼠72只,分为假手术组,HBOP+假手术组,单纯MCAO组、HBOP+MCAO组,每组18只。采用大脑中动脉线栓法建立大鼠MCAO模型。于术后12 h取材,观察大鼠神经功能和脑梗死变化情况;HE染色光镜下观察缺血区脑组织的病理形态学改变。Western blot检测缺血区OPN的表达变化。结果神经功能缺损评分:术后12 h假手术组及HBOP+假手术组评分均为0分,单纯MCAO组(3.80±0.79)分,HBOP+MCAO组(2.50±0.97)分;平衡能力评分:术后12 h假手术组及HBOP+假手术组大鼠平衡能力评分均为5分,单纯MCAO组(1.50±1.08)分,HBOP+MCAO组(2.70±2.95)分;脑梗死率:术后12 h假手术组及HBOP+假手术组大鼠梗死率均为0,单纯MCAO组(49.22±7.07)%,HBOP+MCAO组(41.96±3.15)%。可见与单纯MCAO组比较,HBOP+MCAO组在术后12 h神经功能缺损评分明显降低(P<0.05),平衡能力评分显著提高(P<0.05);脑梗死率明显小于单纯MCAO组(P<0.05);HE染色见缺血区脑组织病理损伤明显减轻;Western blot检测提示OPN的表达显著增强。结论高压氧预适应可以诱导大鼠MCAO后的神经保护作用,其机制可能与HBOP引起的OPN表达增高有关。

Objective To observe the neuroprotective effect of hyperbaric oxygen preconditioning（HBOP） in rats after middle cerebral artery occlusion（MCAO）,and to investigate the effect on osteopontin（OPN） expression.Methods Seventy-two Sprague-Dawley rats were randomly and equally divided into 4 groups including a sham group,a HBOP＋sham group,a simple MCAO group and a HBOP＋MCAO group（n=18）.The neurological deficits and cerebral infarction volume were detected in the rats at 12 h after permanent MCAO.The pathological changes of ischemic regions were observed under a light microscope by HE staining,and the expression of OPN in ischemic regions was determined by Western blotting.Results The scores of neurological deficits at 12 h after MCAO were 0 in the sham and HBOP＋sham groups,3.80±0.79 in the simple MCAO group,and 2.50±0.97 in the HBOP＋MCAO group.The scores of balance ability at 12 hours after MCAO were 5 in the sham and HBOP＋sham groups,1.50±1.08 in the simple MCAO group,and 2.70±2.95 in the HBOP＋MCAO group.The proportions of cerebral infarction volume at 12 hours after MCAO were 0 in the sham and HBOP＋sham groups,49.22±7.07 in the simple MCAO group,and 41.96±3.15 in the HBOP＋MCAO group.Compared with the simple MCAO group,the score of neurological deficits reduced significantly（P0.05）,the score of balance ability increased significantly（P0.05）,and the proportion of cerebral infarction volume was significantly lower in the HBOP＋MCAO group at 12 h after MCAO（P0.05）.The pathological injury of brain tissues in ischemic region was significantly relieved,and the expression of OPN was upregulated in the HBOP＋MCAO group.Conclusion HBOP plays a neuroprotective role in rats after MCAO,and the mechanism may be associated with the upregulation of OPN.