The Study Of Localization Of Connexin43 And Interstitial Cells Of Cajal In Colon In Hirschsprung's Disease

Background and objectiveHirschsprung's diseas(HD) is the commonly encountered disease in Pediatric Surgery. The main clinical symptoms is abdominal distension,constipation and so on. HD is a congenital malformation of embryonic hindgut characterised by the absense of parasympathetic intrisic ganglion cells in the submucosal and myenteric plexuses. The pathophysiology of Hirschsprung's disease is not fully understood. In recently studies,HD is associated with absence or altered distribution of the interstitial cells of Cajal (ICC) and the dysfunction of intercellular communication. Interstitial cells of Cajal are considered as pacemaker cells between gastrointestinal smooth muscles;they can generate spontaneous slow waves of the smooth muscle layers and mediate neurotransmission. It has been reported that the transmembrane protein tyrosinekinase receptor c-kit is essential for the development and function of the ICC. The cellular network of ICC is connected by Gap junctions to each other and to the smooth muscle cells. The basic unit conforming the Gap junction channels is a protein called "Connexin". Connexin43 is regarded as the major Gap junction protein in mammalian vertebrates. In this study we use the technology of immunohistoc-chemisty to investigate the localization of gap juction protein43(Cx43)and c-kit in Hirschsprung's disease(HD) colon. And we investigate ultrastructural organization of ICC and Gap junctions in Transmission electron microscopy.Materials and methods1. We investigate the the distribution of c-kit-positive ICCs and immunohistochemic localization of Gap junction protein Connexin43 in the normal(15) and HD (30)bowel using whole-mount preparation;2. Using the technology of transmission electron microscopy investigate the ultrastructural organization of ICC and Gap junctions in the HD bowel;3. Statistical analysis was carried out by using AVOVA,LSD in measurement data .In qualitation data the statistical analysis was carried out by using X~2-test.α=0.05 was considered as significance.Results1. The expression of c-kit protein in the segments of distent is the same (P=0.535 > 0.05)to that in the segments of normal tissues and higher significantly than those in the segments of stenosis (P<0.01);2. The expression of Cx43 protein in the segments of distent is the same (P=0.458 > 0.05)to that in the segments of normal tissues and higher significantly than those in the segments of stenosis (P<0.01);3. Under electromicroscopic examination, gap junction was absent or less in the aganglionic part of HD, but it could be observed in ganglionic part of HD.Conclusion1. With the absence of ganglion cells, like Hirschsprung's disease lack of Cajal intestinal stromal cells is one of the pathological changes in HD;2. Results of our study show that the abnormal distribution of ICC and Gap Junction protein connexin43 in HD;3. The lack of ICC and connexin43 may be one reason of incidence of HD.