电刺激迷走神经对脓毒症大鼠炎性反应的影响

Effects of electric stimulation of vagus nerves on inflammatory response to sepsis in rats

目的探讨电刺激迷走神经对脓毒症大鼠炎性反应的影响。方法成年雄性SD大鼠40只，采用盲肠结扎穿孔（CLP）法制备脓毒症动物模型。随机分为4组（n=10）：假手术组（S组）不行CLP术，仅分离双侧颈部迷走神经干；CLP组行CLP术和双颈部迷走神经干分离术；VGX组行CLP术及双颈部迷走神经干离断术；STM组行CLP术、双颈部迷走神经干离断术及电刺激。电刺激方法：左侧迷走神经近心端连接刺激电极，于CLP术毕即刻行持续电刺激（电压5V、脉冲宽度2ms、频率1Hz）20min。右侧颈总动脉穿刺置管连续监测平均动脉压（MAP）。于CLP术毕即刻、术后60、120和240min时各组取5只大鼠采集右侧颈总动脉血0．8ml，采用酶联免疫吸附法测定血浆TNF-α浓度，于CLP术后120min另取5只大鼠处死后提取肝组织，采用免疫印迹法测定肝组织NF-kB表达。结果与S组比较，CLP组和VGX组MAP降低，血浆TNF-α浓度及肝组织NF-kB表达升高（P〈0．01）；与CLP组和VGX组比较，STM组MAP升高，血浆TNF-α浓度降低（P〈0．01）。CLP组、VGX组及STM组肝组织NF-kB表达差异无统计学意义（P〉0．05）。结论 电刺激迷走神经可能通过激活胆碱能抗炎通路，减轻脓毒症大鼠炎性反应，其抗炎作用机制与NF-kB无关。

Objective To investigate the effects of electric stimulation of vagus nerves on inflammatory response to sepsis in rats. Methods Forty adult male SD rats weighing 250-300 g were used in this study. The animals were anesthetized with intraperitoneal 20% urethane 1 g/kg. Sepsis was induced by cecal ligation and puncture （CLP）. Bilateral vagus nerves were isolated at neck. Right common carotid artery was cannulated for continuous MAP monitoring. The animals were randomly divided into 4 groups （ n = 10 each） ： group Ⅰ sham operation （S）; groupⅡ CLP; group Ⅲ CLP ＋ bilateral vagus transaction （VGX） and group IV CLP ＋ bilateral vagus transaction ＋ continuous electric stimulation of the proximal end of left vagus （5 V, 2 ms, 1 Hz） × 20 min （STM）. M.AP was recorded every 30 min. Blood samples were taken at 0, 60, 120, 240 min after CLP for determination of serum concentration of TNF-α. Liver specimen was taken at 120 min after CLP for determination of NF-kB expression in 5 animals in each group. Results MAP was significantly lower while serum TNF-α concentration and NF-kB expression in the liver were significantly higher in group Ⅱ （CLP） and Ⅲ （VGX） than in group Ⅰ （sham operation）. MAP was significantly higher and serum TNF-α concentration was significantly lower in groupiv （STM） than in group Ⅱ （CLP）. There was no significant difference in NF-kB expression in the liver among group Ⅱ ,Ⅲ and Ⅳ. Conclusion Cholinergic anti-inflammatory pathway can reduce inflammatory response to sepsis in rats and NF-kB is not involved in the mechanism.