The Expression And Significance Of LN, â…£-C And HA In Smooth Muscle Of Colon In HD

Congenital megacolon is also called Hirschsprung's disease, HD. It's a common gastrointestinal abnormality in children. The morbidity is about 1/5000. The ratio of man and woman is 4:1.The pathologic feature of HD is the absence of ganglion cells that has been attributed to the failure of migration of neural crest cells in the enteric nervous system. If the development of enteric nervous system is influenced by some factors at different development stage, it will result in various type of HD.The cause of the arrest of the crest cells has not been clearly defined. The pathogenesis of HD is kept unknown. Recently HD is regarded as the result of the interaction of inherited factor and environmental factor. It is definite that some genes have relationship with the cause of HD. About 60-70% familial and 10-30% sporadic cases could be explained by gene mutation. However, majority of HD cases cannt be explained by it. It is noticed that the microenvironment in the gut had been changed in HD. Various components of extracellular matrix proteins, including laminin, collagen IV and hyaluronic acid have been shown an abnormal distribution. There are seldom reports of extracellular matrix in the gut in HD children.By means of radioimmunity technique, we study the laminin, collagen IV and hyaluronic acid distribution in HD, and reveal the relationships among them and therole that they play in the development of enteric nervous system. All these will provide people with new thoughts and basis to investigate the pathogenesis of HD.Materials and Methods:We have collected 36 HD bowel speciments and 20 normal bowel speciments (the control group) in children. The resection speciments from 36 HD children included proximal normoganglionic, transitional, distal aganglionic zones.The control speciments were obtained at operation from the trauma in colon in patients.Fresh bowel speciments were kept below -20 immediately after resection and the smooth muscle layer was denuded from the mucosa. The maximum time between resection and freezing was 20 minutes. By means of radioimmunity technoique to assay the content of laminin, collagen IV and hyaluronic acid in the bowel speciments respectively. The results are analysed using SPSS 10.0 statistical software.Results:!. The content of laminin is 460.36?9.89ng per milligram smooth muscle tissue in normoganglionic zone. There is no significant difference between normoganglionic zone and the control group. The content in transitional zone is higher than that in normoganglionic zone (485.89+50.55ng/460.36?9.89ng) (P<0.05). The aganglionic zone has higher content than the transitional zone (513.64?3.00ng/485.89 ?0.55ng)(P<0.05).2. The content of collagen IV in normoganglionic zone is 121.86 ?0.39ng. There is no significant difference between normoganglionic zone and the control group (P<0.05). The transitional zone has higher content than the normoganglionic zone (134.25?0.86ng/121.86?0.39ng) (P<0.05). The aganglionic zone has higher content than the transition zone (177.86 ?21.76ng/134.25 + 20.86ng)(P<0.05). 3. The content of hyaluronic acid is 105.28 ?20.50ng in normoganglionic zone, 112.72 ?21.73ng in transitional zone,l 14.33 + 22.01 in aganglionic zone, 91.45 +14.16ng in the control group, respectively. There is no significant difference among the three groups of normoganglionic zone,transitional zone and aganglionic zone, but they have higher content of HA than that of the control group (P<0.05). 4. There is a positive correlation relationship between LN and IV-C (r=0.423, P<0.01).Conclusions: l.The distribution of laminin may play a important role in thedevelopment of enteric nervous system in HD. 2.The distribution of collagen IV in colon is smilar to that of laminin. It may play a important role in the progress of the development of enteric nervous system.3.The distribution of hyaluronic acid may also have an influence on the development of enteric nerve system. 4.There is a positive correlative relationship between laminin and collagen IV. They may...