Effect of electro-acupuncture at zusanli on thermal and muramyl dipeptide-induced sepsis in rats

Abstract

Objective To investigate the effect of electro- acupuncture at zusanli on scald sepsis in rats. Methods Sixty specific pathogen free(SPF)male Sprague- Dawley rats, weighing 200-250 g, aged 2-3 months were randomly divided into six groups(n= 10 each):control group(C group), muramyl dipeptide(MDP)group, lectro- acupuncture at zusanli(E) group, lectric stimulation of nonacupoint(NE)group, electro- acupuncture at zusanli+α- bungarotoxin(α- BGT) group and only scard (S)group. Sepsis after scald was induced in MDP, E, NE andα- BGT groups. Rats in group C were injected with 1 ml normal saline via the caudal vein, those in E group were given electro- acupuncture at zusanli, those in NE group electro- acupunctured at non- acupoint, those inα- BGT group were injected withα- BGT(1.0μg/kg)into the femoral vein before acupuncture at zusanli, and those in S group were only scalded. The lung specimens and abdominal aortic blood were obtained at 48 h after thermal injury. The changes of lung pathological structure were observed under light microscope and the ultrastructural changes under transmission electron microscope. The arterial blood gas, serum tumor necrosis factor-α (TNF-α),interferon-γ(IFN-γ)and high mobility group protein B1(HMGB1) protein levels were measured. Results The acute lung injury was obvious after scald in rats. As compared with MDP group [serum TNF-α(52±8) ng/L; IFN-γ(42±6) ng/L, HMGB1(33±6)μg/L, Llactate(6.1± 1.5) mmol/L, p H(6.9±0.8)and PaO2(43±6) mm Hg(1 mm Hg= 0.133 k Pa)], electrical stimulation of zusanli significantly decreased the levels of the serum TNF-α(22±3) ng/L, IFN-γ(20 ±4) ng/L, HMGB- 1(11±3)μg/L and lactate(3.2±1.1) mmol/L(P< 0.05), increased the pH(7.3±0.9)and PaO2(60±8) mm Hg of arterial blood(P< 0.05), and alleviated the lung injury. Conclusion In a scald and MDP-induced model of sepsis in rats, electrical stimulation of zusanli could significantly ameliorate acute lung injury through activation of cholinergic anti-inflammatory pathway. Key words: Point ST36; Acute lung injury; Sepsis; Scald