Destruction of the dorsal motor nucleus of the vagus affects lower esophageal sphincter pressure in acid-induced acute esophagitis in a rat model / 中华老年医学杂志

ABSTRACT

Objective:To investigate the impact of the destruction of dorsal motor nucleus of the vagus(DMV)on lower esophageal sphincter pressure in a rat model of acute esophagitis.Methods:A total of 40 male Sprague-Dawley(SD)rats were randomly divided into four groups the control group, sham group, DMV destruction group, DMV destruction + vagal stimulation group.Two weeks after DMV destruction or sham operation, hydrochloric acid with pepsin was perfused into the esophagogastric junction of rats for 90 min, and lower esophageal sphincter pressure was measured before and after operation and 60 min after acid perfusion.Rats in the control group received assessment of lower esophageal sphincter pressure directly.Rats in the DMV destruction + vagus stimulation group were given electric current stimulation for 30 minutes before and after 15 min of esophageal acid perfusion.Rats were sacrificed after 60 min of the acid perfusion.The esophagus was prepared for hematoxylin and eosin(HE)staining, and the degree of inflammation and the expression of inflammatory cytokines were examined.Results:In the DMV destruction group, lower esophageal sphincter pressure decreased 2 weeks after DMV destruction compared with pre-destruction levels(25.9±8.8 cmH 2O vs.34.0±8.9 cmH 2O, P<0.05), and lower esophageal sphincter pressure decreased after 60 min of acid perfusion compared with pre-destruction levels(18.6±3.6 cmH 2O vs.25.9±8.8 cmH 2O, P<0.01). In the DMV destruction + vagus stimulation group, lower esophageal sphincter pressure increased after vagus nerve stimulation(22.3±2.9 cmH 2O vs.18.6±3.6 cmH 2O, P<0.05). There was no significant difference in lower esophageal sphincter pressure in the sham group before and after sham operation, while the pressure increased after acid perfusion(30.0± 9.5 cmH 2O vs.37.8±5.8 cmH 2O, P<0.05). The degree of inflammation in the lower esophagus was aggravated and the expression of tumor necrosis factor-α, interleukin(IL)-6, IL-1β and prostaglandin E2 in esophageal tissues increased in the DMV destruction group compared with the sham group( P<0.01). The inflammation degree and the expression of inflammatory factors in the lower esophagus improved after vagal nerve stimulation compared with pre-stimulation levels( P<0.01). Conclusions:DMV destruction decreases lower esophageal sphincter pressure and aggravates esophageal inflammation and injury in a rat model of acute esophagitis.Vagus nerve stimulation can strengthen the pressure of the lower esophageal sphincter and improve the inflammation of the lower esophageal segment.