Effects of electroacupuncture at"Zusanli"and"Taichong"on gastrointestinal function and brain-gut axis in model rats with functional dyspepsia
Objective We aimed to investigate the effects of electroacupuncture at"Zusanli"(ST36)and"Taichong"(LR3)on gastrointestinal motility,gastrointestinal hormones,and brain-gut axis in rats with functional dyspepsia(FD).Methods 48 SD rats were randomly divided into a normal control group,a model group,a cisapride group,and an electroacupuncture group,with 12 rats in each group.A mild tail pinch stimulation combined with intermittent food deprivation was used to establish the FD rat model.Body mass,food intake,and sucrose preference rate were recorded before and after modeling to verify the success of the FD model.After modeling,the normal control group and the model group received no intervention;the cisapride group rats were administered cisapride[0.4 g/(kg·d)]by intragastric perfusion for 6 consecutive days as one course of treatment,with a rest day between each course;the electroacupuncture group rats received electroacupuncture stimulation at bilateral"Zusanli"and"Taichong"(DC,dense-sparse wave,2/100 Hz,2-5 mA.Electricity was applied for 30 min),with stimulation every 24 h for 6 consecutive times as one course of treatment,with a rest day between each course.After two courses of treatment,samples were collected to compare gastrointestinal motility indices,blood levels of gastrointestinal hormones[motilin,gastrin,serotonin(5-HT),nitric oxide(NO)],serum and tissue levels of endogenous brain-gut peptides[cholecystokinin(CCK),calcitonin gene-related peptide(CGRP),neuropeptide Y(NPY)]in the hypothalamus,gastric antrum,duodenum,colon,and protein expressions of ghrelin and substance P in the hypothalamus,spinal cord,gastric antrum,and colon.Results Body mass,food intake,and sucrose preference rate were lower of the model rats than those of the normal rats(P<0.05).Compared with the model group,rats in the electroacupuncture group and cisapride group had(i)lower gastric residual rates,higher rates of small intestinal propulsion and gastric slow wave main frequency and power(P<0.05);(ii)levels of motilin,gastrin,and 5-HT increased,while NO level decreased(P<0.05);(iii)serum CCK content increased,while CGRP and NPY levels decreased(P<0.05);(iv)CCK protein positive expression increased,while CGRP and NPY protein positive expression decreased in the hypothalamus,gastric antrum,duodenum(P<0.05);(v)ghrelin protein expressions increased,and substance P protein expression decreased in the hypothalamus,spinal cord,gastric antrum,and colon(P<0.05).There were no significant differences in these indicators between the electroacupuncture group and the cisapride group.Conclusion Electroacupuncture at"Zusanli"and"Taichong"can effectively alleviate gastrointestinal motility disorders in FD rats,regulate gastrointestinal hormone levels,reverse abnormal brain-gut peptide expression,and regulate brain-gut interaction balance.