电刺激左右侧迷走神经对感染性休克大鼠血压及肝功能的保护作用

Protective effects of electrical stimulation of left and right efferent vagus on liver function in septic shock rats

目的研究电刺激左右侧迷走神经对感染性休克大鼠肝脏炎性反应的影响。方法采用盲肠结扎穿孔法(CLP)复制感染性休克模型。40只SPF级健康雄性SD大鼠,随机分为5组,每组8只。①假CLP组;②CLP组;③迷切组;④电刺激左侧迷走神经组;⑤电刺激右侧迷走神经组。刺激方法是分别将左、右侧迷走神经远端连接刺激电极,于CLP术毕即刻持续电刺激(5V、2ms和1Hz)20min。各组动物均行颈总动脉置管连续监测平均动脉压,用ELISA法检测肝脏匀浆肿瘤坏死因子α(TNF-α)及血清乙酰基转移酶(AST)、丙氨酸氨基转移酶(ALT)的含量。结果 CLP术后平均动脉血压进行性下降,肝脏匀浆TNF-α水平含量显著升高(各P<0.01);与CLP组比较,电刺激左、右侧组动物平均动脉压下降幅度减轻,肝脏匀浆TNF-α含量显著降低(各P<0.01);电刺激左、右侧组无明显差异。结论电刺激左、右侧组迷走神经能缓解CLP致感染性休克大鼠的进行性血压下降,降低肝脏匀浆TNF-α及血清AST、ALT含量,对肝功能有潜在的保护作用;电刺激左、右侧组迷走神经之间肝脏匀浆TNF-α及血清AST、ALT含量无明显差异。

Objective To study the effect of electrical stimulation of the left and right efferent vagus on liver function of septic shock rats. Methods SD rats were randomly divided into 5 groups：groupⅠ,performed sham operation; group Ⅱ,performed cecum ligation and puncture （CLP） and a comparable sham surgical procedure in which the vagus nerve were isolated but not transected; group Ⅲ,subjected to bilateral cervical vagotomy following cecal ligation and puncture; group Ⅳ,bilateral cervical vagotomy after cecal ligation and puncture,and the left vagus nerve trunk was placed across bipolar electrodes connected to a stimulation module and controlled by an acquisition system; groupⅤ,bilateral cervical vagotomy after cecal ligation and puncture,and the right vagus nerve trunk was placed across bipolar electrodes connected to a stimulation module and controlled by an acquisition system. Stimuli with constant voltage （5 V,2 ms,1 Hz） were applied to the nerve for 20 minutes immediately after the models were operated. Before stimulation the common carotid artery was implanted into a blood pressure transducer for continuous registration of mean arterial blood pressure （MAP）. Blood samples of these rats were collected at 2 h after stimulation in all groups to detect TNF （tumor necrosis factors）-α levels of the homogenate in liver,aspartate aminotransferase （AST） and ALT （alanine transaminase） levels in serum. Results The MAP gradually decreased and the concentration of TNF-α levels of the homogenate in liver,AST and ALT levels in serum significantly increased after cecal ligation and puncture. Electrical stimulation of the left and right efferent vagus nerve significantly increased the MAP and attenuated TNF-α levels of the homogenate in liver,AST and ALT levels in blood serum. Conclusions Direct electrical stimulation of the peripheral left and right vagus nerve can significantly decrease blood pressure and reduce TNF-α levels of the homogenate in liver,AST and ALT levels in serum during septic shock. It might produce a potential protective effect on liver function of septic shock in rats,and there is no difference between the left and right vagus nerve after electrical stimulation.