The Protective Effect Of Vagus Nerve Stimulation In Lipopolysaccharide-induced Acute Lung Injury In Rats

Objective:To detect the protective effect of vagus nerve stimulation(VNS)in lipopolysaccharide(LPS)-induce acute lung injury in rats.Methods:Sixty healthy adult male Sprague-Dawley rats(weight 250±20g)provided by Nanjing Peng Sheng Biological Technology Development Co.Ltd were randomly divided into four groups and each group has 15 rats,these groups include that normal saline group(NS group)? lipopolysaccharide group(LPS group)? vagotomy group(LPS+VNB group)and vagus nerve stimulation group(LPS+VNS group).NS group,inject normal saline 10mg/kg through tail vein,incision of bilateral carotid sheath to separate vagus nerve.LPS group,inject lipopolysaccharide 10mg/kg through tail vein,incision of the leftbilateral carotid sheath to separate vagus nerve.LPS+VNB group,inject lipopolysaccharide 10mg/kg through tail vein,incision of bilateral carotid sheath to separate vagus nerve,cut bilateral vagus nerve and the distal nerve contacting stimulating electrode,do sustained electrical stimulation(1mA,1ms and 10Hz).LPS+VNS group,inject lipopolysaccharide 10mg/kg through tail vein,incision of bilateral carotid sheath to separate vagus nerve and the distal nerve contacting stimulating electrode,do sustained electrical stimulation(1mA,1ms and 10Hz).After giving mechanical ventilation for 120 minutes,execute rats with bloodletting abdominal aorta.Then get lung tissue to observe pathlological changes with HE staining,test IL-1?IL-6?IL-10?TNF-? proteins expression with western blot.and get BALF to analyze the apoptosis of inflammation cells with cytometry.Result:1.In the LPS group,Compared with NS group,cell apoptosis rate in early and late period was significantly increased in BALF(P<0.05),the expression of IL-1?IL-6?IL-10 and TNF-? protein in lung tissue increased(P<0.05);2.In the LPS+VNS group,Compared with the LPS group,cell apoptosis rate in early and late period was significantly decreased in BALF(P<0.05),the expression of IL-1?IL-6?IL-10 and TNF-? protein was significantly decreased(P<0.05);3.In the LPS+VNB group,Compared with the LPS group,cell apoptosis rate in early period was significantly decreased in BALF(P<0.05),cell apoptosis rate in the late period was not significantly decreased(P>0.05).the expression of IL-1?IL-10 protein in lung tissue was significantly decreased(P<0.05),the expression of IL-6 was significantly increased(P<0.05),the expression of TNF-? was not significantly decreased(P>0.05).Compared with the LPS+VNS group,cell apoptosis rate in early and late period was significantly increased in BALF(P<0.05),the expression of IL-1?IL-6?IL-10 and TNF-? protein was significantly increased in lung tissue(P<0.05).Conclusion:1.Lipopolysaccharide can induce lung injury.2.In the lipopolysaccharide-induced lung injury,vagus nerve stimulation can reverse the inflammation response in lung injury,and play a protective role in ALI,its mechanism need further research.