Study On The Effects And Its Mechanisms Of Electroacupuncturing At Zusanli Points (ST36) On Gastrointestinal Dysfunction In Rats With Severe Scald Injury

Objective:1.To investigate effect of electro-acupuncture(EA)at Zusanli points (ST36)on gastrointestinal motility and mucosa blood flow of stomach and intestine in rats with scald injury;2.To find out the mechainism of the gastrointestinal protective effects of EA at Zusanli points,and its relationships to cholinergic anti-inflammatory pathway.Methods:Male Wistar rats were divided into ten groups(each=10).sham-scald group(C),scald injury group(S),electro-acupuncture group(SE), sham-electro-acupuncture group(SSE),Atropine group(SM), Atropine+electro-acupuncture group(SME),bilateral sub-diaphragmatic vagotomy+ electro-acupuncture group(SCE),bilateral sub-diaphragmatic vagotomy(SC). Bilateral Zusanli points(ST36)were electroacupunctured with constant voltage (2-3mA,2-100Hz)for 1 hour approximately 30rain after scald injury.2%Blue DEXTRAN 2000(1ml/100g)was gavaged to ten groups after 35%total body surface area(TBSA)full thickness scald injury.The gastric blood flow and intestinal blood flow by laser Doppler were determined at 2h and 6h post scaled injury.All the animals were sacrificed 2h or 6h after scald injury.Levels of inflammatory mediators (TNF-α,NO and NOS)in intestinal tissue,parameters of organ function(DAO,MPO and MDA),and histopathologic changes in small intestine were determined.Results:1.The gastrointestinal motility ratio and the gastric blood flow and intestinal blood flow were significant lowering by scald injury;2.Compared with S group,SE group resulted in significant elevation of the gastrointestinal motility ratio and the gastric blood flow and intestinal blood flow,which were companied with histopathologic inflammatory changes in small intestine;3.EA at Zusanli points obviously lowered the elevated levels of inflammatory mediators(TNF-α,NO and NOS)and the increased activities of gut related enzymes(DAO),and it also alleviated histopathologic changes in small intestine;4.EA at Zusanli points following the injection of Atropine or bilateral sub-diaphragmatic vagotomy showed less gastrointestinal protective effect and anti-inflammatory.Conclusion:The results indicated that EA at Zusanli points significantly promote gastrointestinal motility,improve the gastrointestinal blood flow,and attenuate histopathologic changes in gastrointestinal tissue,after scald injury.The activation of cholinergic pathway might be one of the mechanisms of EA at Zusanli points exerting the effects of gastrointestinal protection and anti-inflammation.