The effect of vagus nerve stimulation on coagulation in septic rats

Abstract

Objective To investigate the effect of vagus nerve stimulation on coagulation parameters in septic rats. Methods Sepsis model was reproduced by intravenously sublethal dose of lipopolysaccharide (LPS). Ninety-six male Sprague-Dawley rats were randomly divided into four groups: saline group (SHMA); lipopolysaccharide group (LPS); Vogotomy group (VGX) and vagus nerve stimulation grou (VNS). The distal end of the left vagus nerve was electrically stimulated for 20 min after injection of LPS with predefined settings (5 V, 2 ms, 1 Hz) as described previously. Prothrombin time (PT), activated partial thromboplastin time (aPTT), thrombin time (TT), fibrinogen (Fbg) and tumor necrosis factor-α (TNF-α) were measured before injection (0 h) and 2, 4 and 6 h thereafter. Results At the 2nd h after injection of LPS, the plasma TNF-α levels were significantly higher in LPS group and VGX group than those in VNS group[( 316.34 ± 23.96), (325.77 ± 39.77) vs ( 252.72 ± 30.36 ) ng/L, P ＜ 0.05]. In LPS group and VGX group the PT was significantly longer than VNS group at the 6th h after injection ofLPS[( 10.68 ± 0.66), ( 10.72 ± 0.57) vs (9.67 ± 1.04) s,P ＜ 0.05]. At the 2nd h in LPS group and VGX group the aPTT was significantly longer than VNS group[( 23.4 ± 0.5 ), ( 23.9 ± 0.5 ) vs ( 18.4 ±1.1) s,P＜0.05]. At the 4th h in LPS group and VGX group the TT was significantly longer than VNS group[(32.0 ± 1.0), (32.7 ±0.8) vs (28.7 ± 1.9) s,P ＜0.05]. At the 4th h in LPS group and VGX group the levels of Fbg were significantly decreased as compared with VNS group[( 1.909 ± 0.224 ),( 1.822 ± 0.329) vs (2.376 ± 0.138 ) g/L, P ＜ 0.05]. Conclusion Electrical stimulation of the vagus nerve can not only significantly reduce serum TNF-α levels but also improve the coagulation dysfunction in septic rats. Key words: Sepsis; Vagus never; Electrical stimulation; Coagulation; Tumour necrosis factor-α