电刺激迷走神经对感染性休克大鼠急性肺损伤的影响

Effect of electrical stimulation of efferent vagus nerve on acute lung injury in septic shock rats

目的观察通过电刺激迷走神经研究胆碱能抗炎通路对感染性休克大鼠急性肺损伤的保护作用。方法成年雄性SD大鼠40只,随机分为4组:假CLP组(SHAM)、CLP组(CLP)、迷走神经切断组(VGX)、迷走神经电刺激组(STM),每组10只,均采用盲肠结扎穿孔法(CLP)复制感染性休克模型,VGX组CLP后行双侧颈部迷走神经离断术,STM组在CLP基础上将左迷走神经远端连接刺激电极,于CLP术毕即刻予以持续电刺激(5 V、2 ms和1 Hz)20 min。动物均连续监测平均动脉压(MAP),分别在各组模型制备完毕或电刺激后0、1、2和4 h检测血浆肿瘤坏死因子(TNF)-α含量、4 h抽动脉血行血气分析计算呼吸指数和取肺组织观察肺组织病理学变化。结果CLP组和VGX组MAP进行性下降,STM组血压各时间点均显著高于CLP组相应值。STM组血浆TNFα含量显著低于CLP组和VGX组。4 h CLP组和VGX组pH值、PaO_2、PaCO_2和PaO_2/FiO_2显著下降(P<0.01),明显低于假CLP组和STM组(P<0.05)。光镜下CLP组和VGX组肺组织损害明显重于STM组和SHAM组。结论电刺激迷走神经通过胆碱能抗炎通路能逆转CLP致感染性休克大鼠血压下降,降低血清TNFα水平,减轻急性肺损伤所致低氧血症和肺水肿,减轻肺组织病理损害,对肺脏有保护作用。

Objective To investigate the effect of electrical stimulation of efferent vagus nerve on the acute lung injury in septic shock rats. Methods Forty male Sprague-Dawley rats were randomly divid- ed into 4 groups：Group 1 （sham operation） ;group 2 （cecal ligation and puncture, and bilateral cervical vagus nerves were isolated） ;group 3 （bilateral cervical vagotomy following cecal ligation and puncture） ; group 4 （ bilateral cervical vagotomy after cecal ligation and puncture, and the left vagus nerve trunk was stimulated by current （5 V, 2 ms, 1 Hz） continuously for 20 min after the models were made ）. Before stimulation the common carotid artery was implanted into a blood pressure transducer for continuous registration of mean arterial blood pressure （MAP）. Arterial blood samples were collected at 0,1,2 and 4 h after operation for determination of plasma TNF-α concentration and at 4 h for blood analysis. Lung tissue samples were collected for pathological examination. Results Electrical stimulation of efferent vagus nerve significantly attenuated the decrease in MAP and the increase in plasma TNF-α concentration and alleviated inflammation in lung tissue. Conclusion Direct electrical stimulation of the efferent vagus nerve can significantly produce a potential protective effect on acute lung injury in septic shock rats.