电针足三里对烫伤后胞壁酰二肽诱导的大鼠脓毒症的影响

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

目的 观察电针足三里对烫伤后胞壁酰二肽诱导的大鼠脓毒症的影响.方法 健康雄性SD大鼠60只,体质量200 - 250 g,2-3个月龄,随机分为6组（n=10）：对照组（C）、足三里组（E）、胞壁酰二肽组（MDP）、非经非穴组（NE）、α-银环蛇毒素组（α-BGT）和烫伤组（S）.E、MDP、NE及α-BGT组予以烫伤后静脉注射MDP 5 mg/kg构建大鼠烫伤后脓毒症模型.C组尾静脉注射生理盐水1 ml.E组于双侧足三里穴电针刺激;NE组于双侧足三里穴旁5 mm处给予脉冲刺激;α-BGT组股静脉注射α-BGT 1.0 μg/kg后双侧足三里穴给予脉冲刺激,S组仅烫伤处理.各组大鼠于电针后48 h,取腹主动脉血、肺组织,光镜下观察肺组织病理结果;电镜下观察肺组织超微结构的改变;检测大鼠腹主动脉血血气分析、血清肿瘤坏死因子-α（TNF-α）、γ-干扰素（IFN-γ）及高迁移率族蛋白B1（HMGB1）的含量.结果 经烫伤后大鼠急性肺损伤明显,MDP组大鼠血清TNF-α[（52±8） ng/L]、IFN-γ[（42 ±6） ng/L]、HMGB1[（33 ±6）μg/L]和血乳酸（La）值[（6.1±1.5）mmol/L]较S组TNF-α[（39 ±6） ng/L]、IFN-γ[（34 ±6） ng/L]、HMGB1[（25 ±4）μg/L]和血La值[（3.1±1.3）mmol/L]升高（P＜0.05）,血pH值（6.9±0.8）、PaO2[（43 ±6） mmHg（1 mmHg =0.133 kPa）]较S组pH值[7.4±0.6]、PaO2[（59±8）mmHg]降低（P＜0.05）;与MDP组比较,E组大鼠血清TNF-α[（22±3）ng/L]、IFN-γ[（20 ±4） ng/L]、HMGB1[（11±3）μg/L]和血La值[（3.2±1.1）mmol/L]降低（P＜0.05）,动脉血pH值（7.3±0.9）、PaO2[（60 ±8）mmHg]升高（P＜0.05）,肺组织病理损伤明显减轻.结论 MDP可以加重烫伤后大鼠的急性肺损伤及酸中毒,电针足三里穴可减轻烫伤后MDP诱导的脓毒症致大鼠急性肺损伤,机制可能与激活含α7亚基N型胆碱能受体（α7 nAchRs）介导的胆碱能抗炎通路有关.

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 non-acupoint （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 and α-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 in α-BGT group were injected with α-BGT （1.0 μg/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,pH （6.9 ± 0.8） and PaO2 （43 ± 6） mmHg （1 mmHg =0.133 kPa）],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） mmHg 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.