Distribution of NOS nerves and interstitial cells of Cajal in myenteric plexus of human fetal intestine / 第三军医大学学报

ABSTRACT

Objective To investigate the distribution modes of NOS nerves and interstitial cells of Cajal (ICCs) in myenteric plexus of human fetal intestine. Methods Small intestine samples from 12 fetuses were collected for the preparation of whole mount preparations and cryo sections examined by immunocytochemistry for c kit receptor tyrosine kinase and histochemistry for NADPH diaphorase. Results ICCs associated with the myenteric plexus in the fetal small intestine were observed in the shape of spindle or ovoid with two to three slender processes forming an independent and complete cellular network. While NOS positive nerves, which constitute the main neuronal component of ganglia, connecting strands, and nerve fibers, were found within the circular muscle layer and myenteric plexus of the small intestine and the latter was especially rich of this kind of nerves. Most of these positive neurons were Dogiel I type neurons and they often gathered in cluster in the ganglia. Each ganglion contained several to dozens of NOS positive neurons. Although no colocalization of ICCs and NOS positive nerves was found by double staining of whole mount preparations and cryo sections, they were closely distributed. Conclusion Our results indicate that NO released by myenteric plexus, an inhibitory neurotransmitter, may possess the function of regulating ICCs and smooth muscle in late stage of the fetus.