ABSTRACT
Heme oxygenase (HO)-1 has been reported to play a great role in attenuating lung injury during endotoxic shock in our previous research. Although electro-acupuncture has been explored to reduce oxidative stress and decrease inflammatory reaction in animals with endotoxic shock, the mechanism of this effect is still unclear. The aim of this study was to determine whether HO-1 is involved in the effect of electro-acupuncture on the injured lung during endotoxic shock in rabbits. Sixty New England white rabbits were randomly divided into groups C, Z, ES, EA, AP, and EAZ. Before inducing endotoxic shock, group ES received no electro-acupuncture, while group EA received electro-acupuncture at ST36 (zusanli) and BL13 (feishu) acupoints on both sides for five days and group AP received electro-acupuncture (EA) stimulation at a non-acupoint. Groups ES, AP, EA, and EAZ received LPS to replicate the experimental model of injured lung induced by endotoxic shock, and electro-acupuncture was performed throughout the procedure with the same parameter. Groups EAZ and Z received the HO-1 inhibitor, ZnPP-IX, intraperitoneally. The animals were sacrificed by blood-letting at 6 h after LPS administration. The blood samples were collected for serum examination, and the lungs were removed for pathology examination, detection of alveolaer epithelial cell apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL assay), determination of wet to dry ratio, measurement of Evans blue (EB) contents, and determination of HO-1protein and mRNA expression. According to the results, EA at ST36 and BL13 could increase the expression of HO-1. At the same time, index of quantitative assessment (IQA) score and the number of TUNEL-positive cells decreased, while electro-acupuncture at the other points did not exert this effect, and pretreatment with ZnPP-IX in group EAZ suppressed the efficacy of electro-acupuncture preconditioning. In summary, electro-acupuncture stimulation at ST36 and BL13, while not the non-acupoint, could attenuate the lung injury during the endotoxic shock, and this effect was due to increased expression of HO-1.
Subject(s)
Acupuncture Therapy , Acute Lung Injury/therapy , Endotoxins/pharmacology , Heme Oxygenase-1/metabolism , Shock, Septic/chemically induced , Acupuncture Therapy/methods , Acute Lung Injury/etiology , Animals , Disease Models, Animal , Electric Stimulation/methods , Heme Oxygenase-1/antagonists & inhibitors , Male , Malondialdehyde/blood , Oxidative Stress/drug effects , RabbitsABSTRACT
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.