Effect of α 7 nAChR in Electroacupuncture-induced Reduction of Lung Injury Induced by Limb Ischemia-reperfusion in Rabbits
GONG Li-rong,DOMG Shu-an,KAN Yong-xing,YU Jian-bo
Department of Anesthesiology，Tianjin Nankai Hospital Nankai Clinical College of Tianjin Medical University, Tianjin (300270), China
Abstract:
Objective To observe the effect of α 7 nicotinic acetylcholine receptor (α 7 nAChR) in electroacupuncture-induced reduction of lung injury induced by limb ischemia-reperfusion in rabbits. Methods Forty New Zealand white rabbits were randomly divided into 4 groups (n=10 each): Sham operation group, limb ischemia-reperfusion group, electrical acupoint stimulation group and α-bungarotoxin (α-BGT) group. Limb ischemia-reperfusion was induced by clamping bilateral femoral arteries for 3 h followed by 4 hreperfusion. Bilateral electroacupuncture stimulation of Zusanli and Feishu acupoints was performed (intensity of 1–2 mA, frequency of 2/15 Hz, disperse- dense wave) for 30 min once daily for 4 d before establishment of the model and during the course of establishment of the model in electrical acupoint stimulation group and α-BGT group. At 30 min before the model establishment, speci?c α7nAChR inhibitor α-BGT 1 μg/kg was injected intraperitoneally in α-BGT group. Blood samples were taken from the internal carotid artery at 4 h of reperfusion, and the rabbits were sacrificed. The lungs were removed for microscopic examination and for determination of lung injury scores, wet to dry weight ratio (W/D), contents of TNF-α, interleukin-1beta (IL-1 β) and IL-6, and expression of α 7nAChR by Western blotting. Results The lung W/D ratio after 4 h reperfusion in limb ischemia-reperfusion group, electrical acupoint stimulation group and α-BGT group were 6. 89± 1.07, 4.56±0. 75 and 8. 68± 1. 49, respectively. The lung injury scores in above three groups were 7.52±1.05, 4.16±0.68 and 9.23±1.57, respectively. Both lung W/D ratio and lung injury scores in above three groups were signi?cantly higher than that of Sham operation group. TNF-α concentrations [(13.3± 2.3), ( 11.0± 1.6) and (14.1± 3. 0) pg/mg] in limb ischemia- reperfusion group, electrical acupoint stimulation group and α-BGT group were significantly increased compared with Sham operation group [(3.2 ± 0 . 3 ) pg/mg, P < 0 . 05 ], IL- 1 β concentrations [( 9 . 2 ± 2.0), (7.4 ± 1.7) and (10.5 ± 1 . 9 ) pg/mg] in above three groups were significantly increased compared with Sham operation group [( 2 . 1 ± 0 . 5 ) pg/mg, P<0.05], IL-6 concentrations [(14.2±2.3), (11.7±2.0) and (14.8±1.8) pg/mg] in above three groups were significantly increased compared with Sham operation group [(4. 2 ± 0. 7) pg/mg, P < 0. 05], and expression of α 7 nAChR [( 0 . 55 ± 0.09), (0.87 ± 0 . 14 ) and ( 0 . 33 ± 0 . 08 )] in above three groups were significantly up- regulated compared with Sham operation group [( 0 . 23 ± 0 . 04 ), P < 0 . 05 ]. Compared with limb ischemia- reperfusion group, lung W/D ratio, lung injury scores, contents of TNF-α, IL-1β and IL-6 were signi?cantly decreased, and expression of α7nAChR was signi?cantly up-regulated in electrical acupoint stimulation group. Compared with electrical acupoint stimulation group, lung W/D ratio, lung injury scores, contents of TNF-α, IL-1β and IL-6 were signi?cantly increased, and expression of α7nAChR was signi?cantly down-regulated in α-BGT group. Conclusion Up-regulated expression of α7nAChR is involved in electroacupuncture-induced reduction of lung injury induced by limb ischemia-reperfusion in rabbits.
