rhEPO对新生鼠缺氧缺血性脑损伤的神经保护作用

Neuroprotective effects of recombinant human erythropoietin on hypoxic-ischemic brain damage in neonatal rats

目的探讨重组人促红细胞生成素(rhEPO)对新生鼠缺氧缺血性脑损伤的神经保护作用。方法 57只7天龄新生鼠随机分为假手术对照(正常对照组)、缺氧缺血性脑损伤动物模型组(HIBD模型)、rhEPO治疗组。在建立HIBD模型后,rhEPO治疗组立即一次性腹腔注射3 000IU/kg剂量的rhEPO;HIBD模型组注射等量生理盐水;于处置后24h电镜观察脑组织病理形态学变化,流式细胞计检测脑受损局部神经元细胞凋亡情况,实验7天进行短期感觉运动反射评价。结果与正常对照组相比,HIBD模型组光镜下左侧大脑病理损伤明显;HIBD模型组神经细胞凋亡与正常对照组相比增加(28.30±4.80 vs 47.14±6.97,P<0.05),存活细胞减少(72.42±7.93 vs 48.33±8.39,P<0.05);rhEPO治疗组细胞凋亡与HIBD模型组相比减轻(47.14±6.97 vs 36.88±9.43,P<0.05),存活细胞增多(48.33±8.39 vs 60.06±8.32,P<0.05);HIBD模型组悬吊测试、翻正反射、悬崖逃避反射、趋地反射这四项反射与正常对照组相比成绩均较差,提示神经功能受损;rhEPO治疗组翻正反射及悬崖逃避反射时间与HIBD模型组相比缩短,(4.59±0.11 vs 2.84±0.13,10.84±1.26 vs 8.49±1.03,均P<0.05),以上差异均有统计学意义。结论外源性给予rhEPO能够减轻HIBD大鼠脑组织病理损伤,稳定细胞结构,抑制细胞凋亡,改善短期行为学评价,从而发挥其神经保护作用。

Objective To explore the protective effects of recombinant human erythropoietin （rhEPO） on hypoxic-ischemic brain damage in neonatal rats. Methods Fifty-seven 7-day-old Sprague-Dawley rats were randomly assigned to 3 groups： sham-operated group （control group ） , hypoxie-isehemic brain damage model （ HIBD group） and rhEPO-intervention group. Immediately after reparation of HIBD model, the rhEPO-intervention group was injected 3 000U/kg of rhEPO into the abdominal cavity, and the HIBD group was injected the same dose of normal saline. After 24 hours histological changes in brain tissue were observed with electron microscope. Apoptosis of damage neuron was measured by flow cytometry （FCM）. Four separate reflexes were evaluated at 7day. Results Compared with the sham-operated group, the rats in HIBD group showed obvious histo-pathological damage in left brain. The apoptosis of neuron increased （28.30 -±4.80 vs 47.14 ± 6.97, P 〈0.05） and the survived cells decreased （72.42 ± 7.93 vs 48.33 ~ 8.39, P 〈 O. 05 ）. Compared with the HIBD group, the neuronal apoptosis decreased （47.14 ± 6.97 vs 36.88 - 9.43, P 〈 0.05 ） and survived cells increased （48.33 ~ 8.39 vs 60.06 -± 8.32, P 〈 0.05 ） in rhEPO-intervention group. The evaluation on four reflections （suspension test, righting reflex, cliff aversion reflex and tendency reflection） in HIBD group was worse than that in the control group, which indicated nerve function injury. Compared with the HIBD group, the righting reflex and cliff aversion reflex were shortened in rhEPO-intervention group （4.59 ± 0.11 vs 2.84 ± 0.13, 10.84± 1.26 vs 8.49± 1.03, P 〈0.05）. The differences between groups and among groups were all significant. Conclusion Extrinsic rhEPO can reduce pathologic injury of brain tissues in HIBD rats and plays a neuroprotective role through stabilizing cell structure, inhibiting cell apoptosis and improving short-term behavioral assessment.