Protective effect of electrical stimulation of the vagus nerve in lipopolysaccharide­induced acute lung injury in rats.

ABSTRACT

The present study investigated the role of electrical stimulation of the vagus nerve in the acute lung injury (ALI) inflammatory response induced by lipopolysaccharide (LPS) in rats. A rat model of ALI was established using LPS and by connecting an electrode to the left vagus nerve proximal to the heart in order to provide continuous electrical stimulation (1 mA; 1 msec; 10 Hz). After 120 min, the rat lung tissue was stained with hematoxylin and eosin and the expression of inflammatory factors was evaluated by reverse transcription­quantitative PCR and western blot analysis. The change in apoptosis rate in cells from bronchoalveolar lavage fluid (BALF) was analyzed using flow cytometry. The results of the present study demonstrated that inflammatory cell infiltration, alveolar wall and interstitial thickening, and lung hyperemia in rats with LPS­induced ALI were decreased following electrical stimulation of the vagus nerve. Electrical stimulation inhibited the expression levels of IL­1, IL­6, IL­10, IL-8 and TNF­α at both the mRNA and protein levels and decreased early and late apoptosis rates in inflammatory cells from BALF. The results indicated that vagus nerve stimulation can reverse the inflammatory response in lung injury, thereby exerting a pulmonary protective effect.