Effect of electroacupuncture on endoplasmic reticulum stress in lung tissues of rats with acute lung injury induced by endotoxin / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the effect of electroacupuncture on endoplasmic reticulum stress in lung tissues of rats with acute lung injury (ALI) induced by endotoxin.Methods Forty healthy pathogen-free male Sprague-Dawley rats,aged 8 weeks,weighing 180-210 g,were divided into 4 groups (n=10 each) using a random number tablecontrol group (group C),ALI group,electroacupuncture group (group E),and electroacupuncture at non-acupoint group (group NE).Lipopolysaccharide 5 mg/kg (in 0.5 ml normal saline) was injected intravenously to establish the model of endotoxin-induced ALI.Bilateral 30 min electroacupuncture stimulation of Zusanli and Neiguan acupoints was performed with the dispersedense wave (frequency 2/15 Hz,wave length 0.2-0.6 ms,intensity 1-2 mA) once a day (time for stimulation 930-1030) for 4 consecutive days before and during establishment of the model in group E.Electroacupuncture was performed with the same parameters at the points 0.5 cm lateral to the acupoints of Zusanli and Neiguan in group NE.At 6 h after lipopolysaccharide injection,the rats were sacrificed,and lungs were removed for microscopic examination and for determination of wet to dry weight ratio (W/D ratio),apoptosis in alveolar epithelial cells and expression of glucose-regulated protein 78 (GRP78) and CCAAT/enhancer-binding protein homologous protein (CHOP) and caspase-12 in lung tissues (by Western blot).The pathological changes of lungs were scored.Apoptosis index (AI) was calculated.Results Compared with group C,lung injury scores,W/D ratio and AI were significantly increased,and the expression of GRP78,CHOP and caspase-12 in lung tissues was up-regulated in the other three groups (P＜0.05).Compared with group ALI,lung injury scores,W/D ratio and AI were significantly decreased,and the expression of GRP78,CHOP and caspase-12 in lung tissues was down-regulated in group E (P＜0.05),and no significant change was found in the paramneters mentioned above in group NE (P＞0.05).Conclusion The mechanism by which electroacupuncture attenuates endotoxin-induced ALI is related to inhibition of endoplasmic reticulum stress and reduction of apoptosis in alveolar epithelial cells in rats.