【摘要】 【目的】为了比较纯氧与空气复苏对缺氧新生大鼠的复苏效果,探讨新生大鼠肝细胞凋亡及Bcl-2、Bax蛋白表达在缺氧复苏中的作用。【方法】采用SD新生大鼠建立缺氧模型,并分组进行纯氧与空气复苏。实验分为正常对照组(无预缺氧和复氧实验)、纯氧复苏组(PO组)和空气复苏组(RA组)。取肝组织,HE染色光镜观察肝组织病理变化,TUNEL法测定肝细胞凋亡指数,免疫组化检测肝组织Bcl-2、Bax蛋白的表达情况。【结果】与正常对照组相比,PO组可见肝细胞肿胀,肝细胞有部分细胞器缺失,肝细胞呈明显的片状坏死,有炎性细胞浸润,肝细胞索排列紊乱。RA组肝细胞索排列基本正常,肝细胞损伤程度,炎细胞浸润及肝细胞肿胀都较PO组轻。PO24h及72h亚组的细胞凋亡指数分别为(11.2±3.2)%和(9.2±1.0)%,RA24h及72h亚组的细胞凋亡指数分别为(9.0±2.9)%和(7.4±1.9)%,均低于相应的PO各亚组(P<0.01)。PO24h及72h亚组Bcl-2蛋白表达(11.55±1.06)%和(10.49±1.03)%,均低于对应的RA各亚组,RA24h及72h亚组Bcl-2蛋白表达分别为(13.06±2.35)%和(11.71±1.69)%。PO24h及72h亚组Bax蛋白表达分别为(4.81±1.13)%和(4.62±0.79)%,均高于对应的RA各亚组,RA24h及72h亚组Bax蛋白表达分别为(4.08±0.31)%和(3.88±0.48)%。PO组与RA组的细胞凋亡指数、Bcl-2及Bax蛋白表达及Bcl-2/Bax比值差异具有统计学意义(P<0.01),各组内亚组之间差异无统计学意义(P>0.05)。【结论】纯氧复苏较空气复苏后新生大鼠肝细胞的凋亡更严重。纯氧复苏促进Bax基因的表达上调,空气复苏可使凋亡抑制基因Bcl-2表达上调,暗示纯氧复苏对新生大鼠肝的损伤要重于空气复苏。更多还原

【Abstract】 【Objective】 To compare the effects of pure oxygen resuscitation with that of room-air resuscitation on hepatocyte apoptosis and expressions of Bcl-2 and Bax protein. 【Methods】 Neonatal rats were randomly divided into three groups: the normal control group and experimental groups i.e. the room air (RA) group and the pure oxygen (PO) group. After the animal of experimental groups underwent hypoxia and reoxygenation later, liver tissue samples were immediately processed for histological analyses by hematoxylin and eosin staining. Apoptotic index of the hepatocyte was detected by TUNEL assay, and expressions of Bcl-2 and Bax protein in the liver tissues were detected by immunohistochemistry. 【Results】 As compared with those in the normal control group, in PO group liver tissues were swollen, some organelles were lost and obvious flake-like or focal necrosis was emerged. Inflammatory cell infiltrated in the PO group. Though the arrangement of hepatocyte was confused in PO group, but normal in the RA group. Compared with PO group, the morphologies changes of RA group were generally less distinct. The apoptotic index of PO 24 h and 72 h were (11.2 ± 3.2)% and (9.2 ± 1.0)%, while the apoptotic index of RA 24 h and 72 hwere (9.0 ± 2.9)% and (7.4 ± 1.9)%, significantly lower than the corresponding PO subgroups (P < 0.01). The Bcl-2 protein expression of PO 24 h (11.55 ± 1.06)% and 72 h (10.49 ± 1.03)%, were lower than the corresponding RA 24 h (13.06 ± 2.35)% and 72 h (11.71 ± 1.69)%. The Bax protein expression of PO 24 h and 72 h were (4.81 ± 1.13)% and (4.62 ± 0.79)%, higher than the corresponding RA group, which was (4.08 ± 0.31)% and (3.88 ± 0.48)%。 There were statistical significances of apoptotic index, Bcl-2 and Bax protein expression and Bcl-2 / Bax ratio between PO group and RA group (P < 0.01), while no significant difference between 24 h and 72 h with same group (P > 0.05). 【Conclusions】 Hepatocyte apoptosis is more serious using pure oxygen resuscitation than room-air resuscitation. Pure oxygen resuscitation promotes the up-regulation of Bax expression and room-air resuscitation enhances the up-regulation of Bcl-2 expression, suggesting that pure oxygen resuscitation may result in greater damage on hepatic tissues of neonatal rats than room air resuscitation after asphyxia than room-air resuscitation.更多还原