高压氧对缺氧缺血性脑损伤新生大鼠细胞凋亡及Caspase-3 mRNA表达的影响

Effect of hyperbaric oxygen on the apoptosis and the expression of caspase-3 mRNA in neonatal rats with hypoxic-ischemic brain damage

目的 探讨高压氧 (HBO)对缺氧缺血性脑损伤 (HIBD)新生大鼠细胞凋亡及半胱天冬酶 -3m RNA(Caspase- 3m RNA)表达的影响 ,并探讨其可能的机制。方法 健康新生 7d龄 SD大鼠随机分为正常对照组 (CON组 ,n=8) ,左颈总动脉结扎 HIBD组 (n=8)及 HIBD+HBO治疗组 (简称 HBO组 ,n=8)。用免疫组化及原位杂交方法检测各组细胞凋亡及 Caspase- 3m RNA的表达情况。结果 TU NEL 免疫组化结果显示 :CON组的左脑及 HIBD组的右脑未见或偶见阳性细胞 ,HIBD组大鼠左脑组织各个部位均可见到阳性凋亡细胞 ,经 HBO治疗者左脑阳性细胞比未治疗者减少 [(2 5 2 .96± 6 8.5 9)vs(342 .2 4± 74 .16 ) ],差异有显著性意义 (P<0 .0 5 )。Caspase- 3m RNA原位杂交检测结果显示 :CON组无或仅少量阳性细胞出现 ,HIBD组和 HBO组脑皮质、纹状体及海马均可见 Caspase- 3m RNA阳性细胞表达 ,但 HBO组信号明显减少。结论 与 CON组比较 ,HIBD组病变侧脑组织阳性凋亡细胞数增多及Caspase- 3m RNA的表达增强 ;经 HBO治疗后 ,与不经 HBO治疗的 HIBD组比较 ,病变侧脑组织阳性凋亡细胞明显减少 ,Caspase- 3m RNA的表达明显减弱 ,提示 HBO可能通过抑制 Caspase- 3m RNA的表达 ,起到减少细胞凋亡、保护神经元的作用。

Objective To study the effect of hyperbaric oxygen (HBO) on the apoptosis and expression of Caspase-3 mRNA in neonatal rats with hypoxic-ischemic brain damage(HIBD),and to find out the possible mechanism of HBO treatment.Methods Healthy 7-day-old SD rats were randomly divided into 3 groups:normal control group ( n =8),HIBD group ( n =8),HIBD+HBO group ( n =8).The apoptosis and the expression of Caspase-3 mRNA were detected by TUNEL and in situ hybridization technique.Results There were no or little positive apoptotic cells and no or little expression of Caspase-3 mRNA in the normal control group,but much of those in the HIBD group.HBO therapy (HIBD+HBO group) can significantly decrease the positive apoptotic cells[(252.96±68.59) vs (342.24± 74.16), P <0.05] and weaken the expression of Caspase-3 mRNA.Conclusion The number of apoptotic cells and the expression of Caspase-3 mRNA increased obviously in the HIBD group,compared with the normal control group.HBO treatment can decrease the apoptotic cells and weaken the expression of Caspase-3 mRNA,which suggests that HBO probably has a neuronal protecting effect through the above mechanism.