Effects of electro-acupuncture at Zusanli and Feishu on endotoxin shock-induced acute lung injury in rabbits

Objective To evaluate the effect of electro-acupuncture (EA) at Zusanli and Feishu on endotoxin shock-induced acute lung injury in rabbits.Methods Sixty healthy male New Zealand white rabbits aged 2 months weighing 1.5-2.0 kg were randomly divided into 6 groups (n =10 each):group sham operation (group S); group zinc protoporphyrin-Ⅸ (ZnPP-Ⅸ) (group Z); group lipopolysaccharide (LPS) (group L); group LPS + EA (group EL) ; group LPS + sham EA (group SEL) and group LPS + EA + ZnPP-Ⅸ (group ELZ).The animals were anesthetized with intraperitoneal 10％ chloral hydrate 400 mg/kg and tracheostomized.The animals kept spontaneous breathing.Right internal carotid artery was cannulated for BP monitoring.Ear vein was cannulated for drug administration.LPS 5 mg/kg was injected iv in groups L,EL,SEL,ELZ.Endotoxin shock was confirmed by decrease in BP by 20 ％ of the baseline value and PaO2/FiO2 ≤ 300.ZnPP-Ⅸ (heme oxygenase (HO-1 ) inhibitor)10μmol/kg was injected intraperitoneal at 2 h after LPS injection in groups Z and ELZ.Bilateral 15 min EA stimulation of Zusanli and Feishu ( according to atlas of animal acu-points) was performed once a day for 5 days before LPS administration in groups EL and ELZ.The animals were sacrificed by blood-letting at 6 h after LPS administration.The lungs were removed for microscopic examination (0 =no injury,4 =most severe injury),detection of alveolar epithelial cell apoptosis (by TUNEL) and determination of HO-1 protein and mRNA expression.Results LPS significantly increased lung injury scores,alveolar epithelial cell apoptosis index (the number of apoptotic cells/total cells) and HO-1 protein and mRNA expression.EA significantly attenuated lung injury and alveolar epithelial cell apoptosis induced by LPS and further increased the expression of HO-1 protein and mRNA in group EL as compared with group L.The protective effects of EA was counteracted by ZnPP- Ⅸ in group ELZ.Conclusion EA at Zusanli and Feishu can attenuate endotoxin shock-induced lung injury by up-regulation of HO-1 expression and inhibiting alveolar epithelial cell apoptosis in the lung. Key words: Electric stimulation therapy; POINT ST36 (ZUSANLI); POINT BL13 (FEISHU); Shock,septic; Respiratory distress syndrome,adult