Effect Of Electroacupuncture At Zusanli (ST 36) On EC And Visceral Sensitivity In IBS-D Model Rats

Objective:By observing the effects of electroacupuncture at Zusanli point on the changes of colonic muc osal chromaffin cells(EC),5-hydroxytryptamine(5-HT),and tryptophan hydroxylase 1(TPH1)in the tissues of rats with diarrhea irritable bowel syndrome(IBS-D),the mechanism of EC,5-HT,and TPH1 in the regulation of IBS-D by electroacupuncture at Zusanli point was explo red,To provide experimental and theoretical basis for the clinical use of electroacupuncture in the treatment of IBS-D.Methods:Eighteen male SD rats were randomly selected as a blank group,and the remaining 12 rats we re used to establish an IBS-D rat model.The model was established using chronic restraint str ess combined with senna leaf perfusion.The general conditions,body mass growth value,visc eral sensitivity,diarrhea index,and evaluation of the model were observed and measured befo re and after modeling in each group.Subsequently,they were randomly divided into a model group and an electroacupuncture group.The blank group and the model group were grabbed a nd fixed under the same conditions,and then returned to the cage without electroacupuncture i ntervention.The electroacupuncture group was treated with electroacupuncture at Zusanli for20 minutes per day,lasting for 7 days.During the treatment period,the body mass growth val ue,colorectal distension(CRD),abdominal wall retreat reflex(AWR)scores,and diarrhea ind ex of rats were observed to evaluate the improvement effect of electroacupuncture at Zusanli on the symptoms of IBS-D rats.After treatment,the colonic tissues of rats were taken for im munohistochemistry to detect the changes in the number of EC,enzyme linked immunostainin g(ELISA)to detect the expression of 5-HT in the colonic tissues of rats,fluorescent quantitati ve PCR to detect the m RNA expression of TPH1 in rats,and Western blot to detect the expres sion of TPH1 protein in rats.Results:1.Body mass growth: There was no significant difference in the body mass of rats in each gro up before modeling;After modeling,the body mass growth values of rats in the model group and the electroacupuncture group were significantly lower than those in the blank group(P<0.01),while the body mass growth values of the model group and the electroacupuncture group were not statistically significant(P>0.05);After intervention,compared with the model group,the body mass of rats in the electroacupuncture group showed an increasing trend.2.Diarrhea: Before modeling,there was no diarrhea in the three groups of rats.After modeling,compared with the blank group,the diarrhea index in the electroacupuncture group and the m odel group significantly increased(P<0.01),and there was no statistically significant differenc e between the electroacupuncture group and the model group.After intervention,compared w ith the blank group,there was no significant difference in the electroacupuncture group,but th ere was still a significant difference in the model group(P<0.01),and the electroacupuncture group was significantly lower than the model group(P<0.01).3.Visceral sensitivity evaluation: After intervention,the volume thresholds of abdominal contr action,abdominal elevation,and hip elevation in the CRD of the model group rats were signif icantly lower than those of the blank group(P<0.01);Compared with the model group,the thr eshold of abdominal contraction and hip elevation in the electroacupuncture group was signifi cantly increased(P<0.01),and the threshold of abdominal elevation was also increased(P<0.05).Before modeling,there was no statistically significant difference in AWR threshold amon g the three groups of rats at 60 mm Hg.After modeling,the AWR scores of the model group an d the electroacupuncture group were significantly higher than those of the blank group(P<0.05),and there was no statistically significant difference between the electroacupuncture group and the model group.After intervention,the threshold of the electroacupuncture group was si gnificantly lower than that of the model group(P<0.01),and there was no significant differen ce between the electroacupuncture group and the blank group.4.The number of ECs in the model group was significantly higher than that in the blank group(P<0.01),while the expression level in the electroacupuncture group was lower than that in th e model group(P<0.05).5.5-HT concentration: The model group was significantly higher than the blank group(P<0.01),while the electroacupuncture group was significantly lower than the model group(P<0.01).6.Expression of TPHI m RNA: The relative expression of TPH1 m RNA in the model group w as significantly higher than that in the blank group(P<0.01),while the relative expression of TPH1 m RNA in the electroacupuncture group was significantly lower than that in the model g roup(P<0.01).7.Protein expression of TPH1: The protein expression of TPH1 in the model group was higher than that in the blank group(P>0.05);Compared with the model group,the protein expressio n of TPH1 in the electroacupuncture group was relatively lower(P>0.05).Conclusion:1.Electroacupuncture at Zusanli point can reduce visceral sensitivity and improve diarrhea sy mptoms in IBS-D rats,making it one of the effective methods for treating IBS-D.2.The expression levels of EC,5-HT,and TPH1 in the colon tissue of IBS-D model rats incre ased,which may be related to the pathogenesis of IBS-D.3.Electroacupuncture at Zusanli point may regulate visceral sensitivity in IBS-D rats by affect ing EC cells and TPH1 expression,thereby increasing 5-HT levels.