目的：探讨血红蛋白水平对大鼠颅脑损伤后神经细胞凋亡及凋亡相关蛋白的影响。方法将100只健康雄性 SD 大鼠按随机数字表法分为 A、B、C、D、E 组，每组20只。A 组为假手术组，仅行开颅手术；B、C、D、E 组制作大鼠颅脑损伤模型，并放血使血红蛋白（Hb）控制在相应范围（B 组：Hb＜70 g·L－1，C 组：70 g·L－1≤Hb＜90 g· L－1，D 组：90 g·L－1≤Hb＜120 g·L－1，E 组：Hb≥120 g·L－1）。采用 TUNEL 法检测脑组织细胞凋亡，免疫组化检测 Bcl-2、Bax 蛋白表达。结果与 A 组比较，B、C、D、E 组细胞凋亡率均显著增加，Bcl-2、Bax 蛋白阳性表达率均显著增高（P ＜0．05）；与 E 组比较，B、C 组细胞凋亡率、Bax／Bcl-2比值均显著增加（P ＜0．05）。结论大鼠颅脑损伤后 Hb＜90 g·L－1可使 Bax／Bcl-2比值明显增加，促进神经细胞凋亡。%ABSTRACT:Objective To investigate the effects of hemoglobin (Hb)levels on neuronal apopto-sis and apoptosis-related protein expression in rats after traumatic brain injury.Methods One hundred healthy male SD rats were randomly divided into five groups:A (sham operation),B (Hb<70 g·L-1 ),C (70 g·L-1 ≤Hb<90 g·L-1 ),D (90 g·L-1 ≤Hb<120 g·L-1 )and E (Hb≥120 g· L-1 ),with 20 rats in each group.Rats in group A received craniotomy only.Traumatic brain injury was induced in other groups and blood letting was performed to maintain Hb levels in the corresponding range.Nerve cell apoptosis was measured using TUNEL assay.The expression of Bcl-2 and Bax was measured using immunohistochemistry.Results Compared with sham oper-ation group,the apoptosis index and the expression of Bcl-2 and Bax significantly increased in rats with traumatic brain injury (P <0.05).Compared with group E,apoptosis index and Bax/Bcl-2 ratio significantly increased in group B and group C (P <0.05).Conclusion The decrease in Hb levels (<90 g·L-1 )can increase Bax/Bcl-2 ratio and promote nerve cell apoptosis in rats after traumatic brain injury.
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