Hemin对缺氧缺血性脑损伤新生鼠脑保护作用的研究

摘要

Objective To observe the effects of Hemin on neuroglobin (Ngb) expression in neonate rats with hypoxic-ischemic brain damage,and to study the neuroprotective effect and mechanism of Hemin. Methods Ninety neonate SD rats of 7-day-old were divided into 3 groups randomly,inclouding sham operation group, hypoxic-ischemic brain damage group (HIBD group), HIBD plus Hemin group (HIBD+Hemin group).Ligation of the left carotid artery, and hypoxia-inducible(8%oxygen,32℃) 2 h for the HIBD model.After 2 hours of HIBD model establishing,the rats of HIBD+Hemin group was intraperitoneal injected Hemin (50 mg/kg); sham operation group and HIBD group were intraperitoneal injected normal saline. Rats were killed at 24h after operation.Brain were obtained for detecting the infarcted tissue volume percentage,Ngb mRNA expression were detected by RT-PCR and Ngb protein expression were determined by immunohistochemistry. Results Compared to sham operation group, the brain infarcted tissue volume percentage, the expression of Ngb mRNA and Ngb significantly increased (P<0.01);Compared to HIBD group,Ngb mRNA and Ngb expression of HIBD+Hemin group were increased (P<0.05),while the brain infarcted tissue volume percentage was significantly reduced (P<0.05). Conclusion Hemin has neuroprotective effects on neonate rats with hypoxic-ischemic brain damage,which is associated with enhanced expression of neuroglobin.%　　目的观察氯化高铁血红素（Hemin）对缺氧缺血性脑损伤（HIBD）新生大鼠脑组织中脑红蛋白（Ngb）表达的影响，探讨Hemin的脑保护作用及机制。方法将7 d龄新生SD大鼠90只随机分为假手术组、HIBD组、HIBD+Hemin组共3组。采用结扎左颈总动脉、低氧诱导（8%氧气，32℃）2 h方法建立HIBD模型。HIBD建模后2 h，HIBD+Hemin组腹腔注射Hemin（50 mg/kg），假手术组与HIBD组腹腔注射生理盐水。24 h后处死取脑，分别行脑梗死体积百分比测定、荧光定量（RT-PCR）检测Ngb mRNA表达、免疫组化分析Ngb表达。结果 HIBD组和HIBD+Hemin组脑梗死体积百分比、Ngb mRNA和Ngb表达均较假手术组显著上升（P<0.01）；与HIBD组比较，HIBD+Hemin组Ngb mRNA和Ngb表达均增加，而脑梗死体积百分比明显减少，差异均具有统计学意义（P<0.05）。结论 Hemin可减轻新生鼠的缺氧缺血性脑损伤，其机制可能是通过上调Ngb的表达发挥作用。