Ultra-Structural Features of Interstitial Cells of Cajal in Fetal Enteron / 实用儿科临床杂志

ABSTRACT

Objective To study the ultra-structural features of interstitial cajal cells (ICC)in fetal enteron and then classify them.Methods Ultra-structural features of ICC in fetal enteron with spontaneous abortion or premature birth were detected under JEM-2000EX transmission electron microscope for the cause of fetal death, including two fetus specimens of a gestation 18 months and 28 months stained with lead nitrate and uranium acetate.Results ICC had a big oval karyon and a little of cytoplasm. ICC formed spindle or stellate cells with 2 to 5 long cell processes . From the esophagus to the terminal ileum ICC mostly had the same ultra-structural features, but with mitochondria and a well-developed endoplasmic reticulum and Golgi complex in the whole colon and the rectum , more than those of esophagus and small intestine. In the whole colon and rectum ICC had similar ultra-structural features. ICC also possessed an abundance of mitochondria and a well-developed endoplasmic reticulum and Golgi complex. ICC also possessed Caveloae lipid droplet with more electron dense and heterochromatin. Two types of ICC were identified under 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 was bipolar cells which extended to 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 muscles . The second type of ICC in the myenteric plexus and longitudinal muscle layer was 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 nerve cells and smooth muscle cells were connected with gap-like junction, which was the main connection mode .Conclusions The ultra-structural features of ICC in fetal enteron varied with the diffe-rent locus and different tissue sheets in the enteron. The mitochondria and a well-developed endoplasmic reticulum and Golgi complex of the whole colon and rectum are more and more developed than that of esophagus and small intestine. Ultra-structural features of ICC will develop further with the gestational age. The gap- like junction among ICC nerve cell and smooth muscle cell are highly important for ICC to educe function.