Study The Development And Ultrastructural Features Of Interstitial Cells Of Cajal In Fetal Enteron

Objective ICC are special cells between autonomic nerve ending andsmooth muscle cell. There were many nerve stretch receptors, such as c-kit, CD34 and so on in the cellular membrane. Abnormal ICC included abnormal distribution decreased number and dysfunction which were primary factors causing disorders of gastrointestinal motility such as slow transit constipation idiopathic intestinal pseudo-obstruction et al. The documents of ICC in development and ultrastructural features were lacked now. In this study we wanted to study the development in distribution of interstitial cells of Cajal in fetal small bowel and colon and the ultrastructural features of interstitial cells of Cajal in fetal enteron and then class them. There might important significance in order to identify etiological factor of disorders of gastrointestinal motility and the function of ICC.Method (1) We have studied the distribution of interstitial cells of Cajal infetal intestine by immunohistochemistry using c-kit antibodies. (2) We have studied the ultrastructural features of interstitial cells of Cajal in fetal enteron that they had been spontaneous abortion or premature birth because of fetaldeath, including two fetus specimen of a gestation 18 month and 28 month .Using JEM-2000EX transmission electron microscope.Result 1. Immunohistochemistry result: from 3 to 4 month of fetal, ICChad similar density in the duodenum jejunum and ileum. ICC formed an incomplete layer associated along the myenteric plexus in spindle-shape with short processes. No ICC was seen in muscular layer and deep muscular plexus. In the whole colon ICC had similar density. A few ICC were seen in the myenteric plexus and longitudinal muscle layer. ICC associated with the myenteric plexus and formed an incomplete network. In the longitudinal muscle layer ICC were mainly parallel to the muscle fibers. There were no ICC in circular muscle layer, mucosa and submucosa layers but few in serosa layer. Between 5 and 6 month, in the small bowel, ICC had similar density but the density of ICC significantly greater at myenteric plexus than muscle layer. ICC formed a continue layer associated along the myenteric plexus . A few ICC were seen in the muscle layer and the ICC were often inparallel orientation with the muscle fibers. The cell body enlarged and the processes elongated. In the whole colon. ICC had similar density but the density of ICC significantly greater at myenteric plexus and longitudinal muscle layer than circular muscle layer, mucosa and submucosa layers and serosa layer. ICC formed a continue layer associated along the myenteric plexus and there were more ICC in the longitudinal muscle layer than that of 3 to 4 month of fetal. A few ICC were seen in the circular muscle layer and the ICC were often inparallel orientation with the muscle fibers. There were no ICC in mucosa and submucosa layers but a few in serosa layer. 7 to 8 month fetal, in the intestine ICC formed dense network in the myenteric plexus and longitudinal muscle layer and loose network in circular muscle layer. Occasional ICC wereseen in the submucosa plexus. The number of ICC rose in serosa layer. 2. Transmission electron microscope result: (1) ICC have a big oval karyon and a little of cytoplasm. ICC formed spindle or stellate cells with 2 to 5 long processes . (2) From the esophagus to the terminal ileum ICC mostly have the same ultrastructural features, but the mitochondria and a well-developed endoplasmic reticulum and Golgi complex of the whole colon and rectum were more developed and more than that of esophagus and small intestine. In the whole colon and rectum ICC had similar ultrastructural features. ICC also possessed an abundance of mitochondria and a well-developed endoplasmic reticulum and Golgi complex. ICC also possessed Caveloae lipid droplet more electron dense and heterochromatin. (3) Two types of ICC were identified using JEM-2000EX transmission electron microscope. One type was present from the esophagus to the terminal ileum and the other type was observed in the colon and rectum. The first type ICC In circular muscle layer were bipolar cells which extended tapering processes in opposite directions. These processes rarely branched, and their appearance was similar to smooth muscle cells Most of them ran parallel to the circular. The second type of ICC in the myenteric plexus and longitudinal muscle layer were mostly multipolar and rarely bipolar cells with long processes. They showed an irregular appearance characterized by numerous short spike-like branches. Processes of multipolar cells extended in every direction and connected with each other ICC. (D Nerve cell and smooth muscle cell connected with like gap junction, which was the main connection mode.Conclusion:1. ICC development varies throughout the gut with the different gestatational age and gut. ICC were located primarily in relation to the...