The Role Of Enteric Nervous System (ENS) Regulation Of Intestinal Secretion Function In Rat With IBS-C

Background and Abstract: Irritable bowel syndrome(IBS) is a functional bowel disorder in which abdominal pain/discomfort is associated with altered defecation and/or bowel habits in absence of demonstrable pathological changes.IBS can be divided into four subtypes,diarrhea,constipation,mixed and unsubtyped. Its pathophysiological mechanisms remain unclear.A majority of gut motor function have been pay attention on by clinicians and researchers,while the changed of the Enteric Nervous System (ENS) regulation of intestinal secretion function in ite pathogenesis maybe also palys an important role. The objective of our research was to establish an IBS-C rat model with ice water and via Immunofluorescence staining to verify the activation status of specific secretory motor neurons in the IBS-C rat model’ s ENS. What’ s more, via Ussing Chamber system to study that submucous plexus(SMP) how to regulate the intestinal secretion and the changes of its.Materials and Method:1.Rat models with IBS-C were established with ice water. Used the change of rats’ weight,fecal pellets and its water content,and gastrointinal transmission function to evaluate. Rat intestinal specimens were made respectively to make the colon SMP ’ s whole layer tablet and the separation of colon mucosa specimen with intact SMP.2.Application of multiple Immunofluorescence staining technique for detecting the colon SMP’ s whole layer tablet the total number of neurons,the total number of ganglion,the total number of the activation neurons and the total number of the neurons expressing specific neurochemicalmarkers( ChAT,VIP,NOS) and their colocalization with Anti-Hu antibody,which is the hallmark for whole enteric neurions ,and so on. To evaluate the changes of excitatory and inhibitory motor neuons of SMP in colon ENS of IBS-C model rat.3.Application of Ussing Chamber system and Electrical Field Stimulation(EFS) to investigate the effect of SMP on the regulation of the secretory function of colonic mucosa in the rats with IBS-C, and the relationship between thes e changes and the neurotransmitter(Ach,VIP)related to the intestinal secretion.Results:1.The rats of whoes stomach irritation with ice water has the slower weight growth rate and the less number of feces granules and moisture contents of feces,the slower intestinal transmission.This model rats had some chacteristic of IBS-C.2.In the colon SMP of rat with IBS-C group,the whole number of enteric neurions, the total number of Activated neuron (24.3 ± 12.7 vs 19.9 ± 9.6,P<0.05,n=7) and the Activated NOS-IR neurons (12.4 ± 7.2 vs 9.6 ±5.5,P<0.05,n=7) increased. The Activated ChAT-IR neurons ( 49.0±15.8% vs 56.6 ± 12.6%,P<0.05,n=7) , the Activated VIP-IR (12.4 ± 7.2 vs 9.6 ±5.5,P<0.05,n=7) neurons decreased significantly comparing with control.3.In the model group, the inhibition rate of TTX on EFS was increased at the two phases(P1:98.3%±40.0% vs 87.9%±43.6%;P2:81.7%±36.0% vs 74.9% ± 30.4%, P<0.05,n=6) and the inhibition rate of atropine on EFS’ s P1 compared with its control were all significantly increased,but in between the two group no significantly difference. After blocking SMP,the short current induced by Carbachol (129.6 ± 75.4 μ A/cm2 vs 123.3 ± 55.7 μ A/cm2,n=8,P>0.05) and VIP (160.5± 100.6 μ A/cm2 vs 147.9±74.2 μ A/cm2,P>0.05 ) were not significantly difference between the two groups.Conclusion:1.This rat model was able to simulated the characterics of IBS-C intestinal function.2.The activated of i nh i b i tory Secretory motor neuron in SMP may the most important factor for the constipation symptom of IBS.3.There’ re no significant changes in intestinal secretion function of IBS-C.4.ENS may be involved in the regulation of intestinal secretory function of IBS-C,but it has little regulationship with the activity of SMP,and may have other effects.These discoveries will help to provide a scientific basis of the understanding of the pathogenesis of IBS and as a potential target for the treatment of IBS in the future,which is helpful to the understanding of the mechanism of ENS regulation of intestian secretion function.