电针足三里对腹泻型肠易激综合征模型大鼠EC细胞及内脏敏感性的影响

Effect of Electroacupuncture at Zusanli(ST36)on EC Cells and Visceral Sensitivity in Diarrhea-Predominant Irritable Bowel Syndrome Model Rats

目的:探究电针刺激大鼠足三里穴对腹泻型肠易激综合征(IBS-D)模型大鼠EC细胞、5-HT、TPH1的影响,分析其作用机制。方法:18只成年雄性大鼠,随机分为空白组6只和造模组12只,造模组采用慢性束缚应激联合番泻叶灌胃法建立IBS-D模型;造模成功后,12只大鼠随机分为模型组和电针组各6只,空白组和模型组不予电针干预,电针组进行足三里穴的电针刺激,每日1次,留针20 min,持续进行7 d。观察大鼠体质量增长值、结直肠扩张(CRD)和腹壁撤退反射(AWR)评分、腹泻指数,并运用免疫组化检测EC细胞数量的变化,ELISA检测5-HT表达水平,PCR检测TPH1 mRNA表达情况,Western blot检测大鼠TPH1蛋白的表达情况。结果:与空白组比较,模型组大鼠体质量增长值明显降低,腹泻指数显著升高,CRD容量阈值降低,AWR评分升高,EC细胞数量、5-HT浓度、TPH1 mRNA增高(P<0.01,P<0.05)。与模型组比较,电针组大鼠腹泻指数降低,CRD容量阈值升高,AWR评分降低,EC细胞数量、5-HT浓度、TPH1 mRNA降低(P<0.01,P<0.05)。结论:电针足三里穴能降低IBS-D大鼠内脏敏感性,有效减轻腹泻症状,其作用机制可能是影响EC细胞、TPH1的表达,促使5-HT表达水平下降,从而调控IBS-D大鼠内脏敏感性。

Objective:To explore the effects of electroacupuncture stimulation at the Zusanli(ST36)point on EC cells,serotonin(5-HT),and tryptophan hydroxylase 1(TPH1)in diarrhea-predominant irritable bowel syndrome(IBS-D)model rats and analyze the underlying mechanisms.Methods:Eighteen adult male rats were randomly divided into a control group(6 rats)and a model group(12 rats).The IBS-D model was established in the model group using chronic restraint stress combined with castor oil gavage.After successful modeling,the 12 rats were randomly divided into a model group and an electroacupuncture group(6 rats each).The control and model groups did not receive electroacupuncture,while the electroacupuncture group received daily electroacupuncture at Zusanli point for 20 minutes each day for 7 days.We observed body weight gain,colonic rectal distension(CRD)and abdominal withdrawal reflex(AWR)scores,diarrhea index,EC cell numbers,5-HT levels,TPH1 mRNA expression,and TPH1 protein expression using immunohistochemistry,ELISA,PCR,and Western blot techniques,respectively.Results:Compared to the control group,the model group showed a significant decrease in body weight gain,an increase in the diarrhea index,a reduction in CRD volume threshold,and an increase in AWR scores.EC cell numbers,5-HT concentrations,and TPH1 mRNA levels were also elevated(P<0.01,P<0.05).Compared to the model group,the electroacupuncture group had a reduced diarrhea index,an increased CRD volume threshold,a decreased AWR score,and lower EC cell numbers,5-HT concentrations,and TPH1 mRNA(P<0.01,P<0.05).Conclusion:Electroacupuncture at the Zusanli(ST36)point can reduce visceral sensitivity in IBS-D rats and effectively alleviate diarrhea symptoms.The mechanism may involve modulation of EC cell numbers and TPH1 expression,leading to a decrease in 5-HT levels and subsequent regulation of visceral sensitivity in IBS-D rats.