Effect of Efferent Vagus Nerve Excitation by Electrical Stimulation on Acute Liver Injury in Rabbits with Endotoxemia

Abstract：Objective:To study the effect of electrical stimulation of efferent vagus nerve on the acute liver injury induced by endotoxemia in rabbits. Methods: Sixteen rabbits were randomly divided into stimulation group( Group A, n = 8) and control group ( Group B, n = 8) .They were subjected to bilateral cervical vagotomy and intravenously challenged by lipopolysaccharide (LPS) (E. coli 0111:B4,DIFCO, USA) at a dose of 100 μg/kg injected within 30 min. The distal end of the left vagus nerve trtmk was placed across bipolar electrodes connected to a stimulation module and controlled by an acquisition system. Stimuli with constant voltage ( 10V, 5Hz, 5ms) were applied twice to the nerve for 10min before and after the administration of LPS in Group A. At the time 30,60,120,180.240. 300 min before and after infusion of LPS respectively in each animal, blood samples were taken for late measurement of the serum Alanine aminotransferase ( ALT). Aspartate aminotransferase ( AST), tumor necrosis factor-α(TNF-α) and interleukin- 10 ( IL- 10 ). Immediately after the experiment was finished, autopsy was performed and liver samples were taken to pathologic study.Results: Compared with Group B, the electrical stimulation of efferent vagus nerve could significantly decrease the contents of ALT, AST and TNF-α, but increase the contents of IL-10, in serum of Group A. It could also alleviate inflammation of liver tissue after LPS attack. Conclusion: The results suggest that excitation of the efferent vagus nerve can inhibit the inflammation cascade in liver after LPS challenge. Thus, it might have a protective effect on acute liver damage caused by endotoxemia.