Effect Of Pre-electroacupuncture ST36 On Gastrointestinal Motility And Expression Of Smooth Muscle Cytoskeleton Protein In Diarrhea-predominant Irritable Bowel Syndrome Model Rats

ObjectIn this study,Diarrhea-predominant Irritable Bowel Syndrome?IBS-D?model rats were taken as the research object,smooth muscle cytoskeleton protein was used as the entry point,and under the guidance of the idea of treating non-disease,the model rats were treated by electroacupuncture ST36.To observe the general situation,behavioral changes,changes in gastrointestinal motility,and cytoskeleton protein expression levels in rats,and to explore the possible mechanism of pre-electroacupuncture ST36 in regulating the prevention and treatment of IBS-D by smooth muscle cytoskeleton,so as to provide experimental basis for the prevention and treatment of IBS-D by acupuncture.Method60 3-month-old SPF Wistar rats with a weight of 160-180g were randomly divided into four groups with 15 in each group after one week of adaptive feeding.Namely NC group,model group,pre-electroacupuncture group,fake electroacupuncture group.IBS-D rat model was prepared by the combination of high lactose feeding and chronic unpredictable stimulation,and the modeling time was 28 days.At the same time,the rats were treated with the acupuncture treatment.The NC group was fed with normal feed without any treatment.At the same time,the model group was trained to grasp and to put on and off the mouse clothes.In the electroacupuncture group,both sides of the foot were treated with electroacupuncture at the same time,continuous wave 2Hz,current intensity 1mA,once a day,each time for 15 minutes.At the same time of modeling,the fake electroacupuncture group was treated with electroacupuncture in ST36,but the needle was only inserted into the skin for0.5mm.The treatment was performed once a day for 15 minutes each time.After the modeling and intervention,the general situation,behavioral changes,gastrointestinal motility changes,in vitro colonic contraction changes,SM22?and F/G-actin expression levels of the rats were observed,and the data of each group were statistically analyzed.Results1.Observation of behavioral and IBS-D specific indicators of rats in each group:in the early stage of modeling and intervention,rats in each group except the NC group ate less and drank less,their feces gradually became loose and their moods became irritable.At the late stage of modeling and intervention,the rats in the pre-electroacupuncture group gradually improved,the intake of food and water increased,and the excrement changed from thin to dry.After the modeling and intervention,the AWR pain threshold of rats in the model group was significantly lower than that in the blank group,with a statistically significant difference?P<0.05?,indicating that the visceral sensitivity of rats in the model group was significantly higher than that in the blank group,consistent with the characteristics of IBS-D model.The AWR pain threshold of the pre-electroacupuncture group was significantly higher than that of the model group?P<0.05?,suggesting that the pre-electroacupuncture ST36 could improve the visceral hypersensitivity of IBS-D model rats,but it was still different from that of the NC group?P<0.05?.In the first two weeks before intervention and modeling,the fecal water content of all the three groups except the blank group showed an increasing trend,and the difference between the fecal water content and that of the NC group was statistically significant?P<0.05?.In the third week,the fecal water content of the pre-electroacupuncture group was significantly lower than that of the model group and the fake electroacupuncture group?P<0.05?.In the last week,the fecal water content of the pre-electroacupuncture group still showed a downward trend,and gradually approached to the fecal water content of the normal group,but there was still a significant difference compared with the blank group?P<0.05?.2.Observation of gastrointestinal dynamics,in vitro colon contraction of each group:model group rats gastric emptying rate significantly decreased in the NC group?P<0.05?,and small intestinal propulsion rates significantly speed up?P<0.05?,the curative group although the rate of gastric emptying and small intestinal propulsion rates compared with model group and fake acupuncture group improved significantly positive,but the general gastrointestinal function still fail to restore to the blank group?P<0.05?.Under low concentration stimulation,there was no significant difference in the maximum tension of isolated colonic muscle strips between the four groups?P>0.05?.Under the stimulation of 10^-6mol/L Ach,the contractile tension of isolated colonic muscle strips was significantly increased in the model group and the fake electroacupuncture group under drug stimulation,which was significantly different from that in the NC group and the pre-electroacupuncture group?P<0.05?.However,although the isolated colonic muscle strips in the electroacupuncture group and the NC group responded to the stimulation,there was no statistical difference between the two groups?P>0.05?.After the stimulation intensity was increased again,the contractile tension of isolated colonic muscle strips increased significantly in the model group and the fake electroacupuncture group,and the difference was statistically significant compared with the NC group and the pre-electroacupuncture group?P<0.05?.The contractility of isolated colonic muscle strips in the pre-electroacupuncture group for strong stimulation was significantly higher than that for weak stimulation,and the difference was statistically significant compared with the NC group?P<0.05?.3.Observation of cytoskeletal proteins in colon tissues of rats in each group:protein expression in SM22 and F/G-actin ratio in model group were significantly increased compared with that in NC group?P<0.05?.The protein expression of SM22 and the F/g-actin ratio were significantly decreased in the pre-electroacupuncture group after treatment with electroacupuncture in ST36,which was statistically significant compared with the model group,but also statistically significant compared with the NC group?P<0.05?.ConclusionPre-electroacupuncture ST36 can improve behavioral symptoms of IBS-D rats,positively regulate gastrointestinal motility,down-regulate SM22a and F/g-actin expression,and improve abnormal smooth muscle contraction.