重组人促红细胞生成素对L5脊神经切断大鼠痛阈及脊髓TNF-α和IL-1β表达的影响

Effects of rhEPO on pain threshold and spinal expression of TNF-α and IL-1β in rats with L5 nerve transection

目的 观察重组人促红细胞生成素（rhEPO）对L5脊神经切断大鼠机械和热痛阈及脊髓TNF-α和IL-1β表达的影响.方法 SD雄性大鼠50只随机分为五组：脊神经损伤rhEPO1 000、3 000、5 000 U/kg组（R1、R2、R3组）和生理盐水组（N组）及假手术组（C组）,每组10只.术前1 d给药,连续7 d.测定术前当天及术后3、7、14 d大鼠的机械性缩足反射阈值（MWT）和热缩足潜伏期（TWL）及术后14 d各组大鼠L5脊髓肿瘤坏死因子α（TNF-α）、白细胞介素1β（IL-1β）的水平.结果 L5脊神经损伤术后大鼠术侧MWT降低、TWL缩短、脊髓TNF-α和IL-1β的表达增高（P〈0.01）.与N组比较,R1组术后各时间点的MWT和TWL无明显改变;R2和R3组MWT增高、TWL延长（P〈0.05）;脊髓TNF-α、IL-1β水平降低（P〈0.01）.结论 腹腔注射rhEPO 3 000或5 000U/kg能缓解L5脊神经切断大鼠的机械和热痛敏,抑制脊髓TNF-α和IL-1β的表达.

Objective To observe the effects of recombinant human erythropoietin （rhEPO） on pain threshold and spinal expression of TNF-α and IL-1βin rats with L5 spinal nerve transaction （SNT）. Methods Fifty male Sprague-Dawley rats were randomized into 5 groups of rhEPO 1 000, 3 000, 5 000 U/kg （R1, R2, R3） saline （N） with SNT and saline with sham operation （C） with ten rats each. The intraperitoneal administration of rhEPO or saline was started from the day before surgery for 7 days. Mechanical withdrawn] threshold （MWT） and thermal withdrawal latency （TWL） of rats were measured on postoperative days 3, 7, and 14, respectively. Spinal expression of TNF-α and IL-1β was measured on postoperative day 14. Results The rats wth SNT had lower MWT and TWL as well as higher spinal expression of TNF-α and IL-1β （P〈0. 01）. Compared with group N, MWT and TWL had no significant changes at every time points in group R1 ; while groups R2 and R3 had increased MWT and TWL （P〈0.05） as well as decreased TNF-α and IL-1β （P〈0.01）. Conclusion Intraperitoneal administration of rhEPO 3000 or 5000 U/kg can attenuate the mechanical and thermal hyperalgesia, and inhibit the spinal expression of TNF-α and IL-1β in rats with SNT.