ABSTRACT
This study was performed to investigate the morphometric changes of myenteric plexus and type 1 interstitial cells of Cajal (ICC-I) in regeneration process of small intestine transection. Sprague Dawley rats (200~250 g) were anesthetized with ether; then the full thickness of ileal wall were semitransected; and subsequent end-to-end anastomosis were performed by using 6-0 silk suture thread. Sham-operated rats, which only underwent the laparotomy, were used for control group. Experimental animals were sacrificed at 3 days, 7 days, 15 days, and 30 days after the operation. In each group myenteric plexus and ICC-Is were prepared by histochemical method (NADH-TR stain for myenteric plexus, ZIO stain for ICC-Is) and cell numbers were counted by image analyzer (Image plus pro-5.0, Media Cybermedics, USA). Degeneration of myenteric neurons and ICC-Is occurred simultaneously and it was similar in oral and anal to the site of transection. Degeneration effects were most prominent at 3 days and 7 days after intestinal transection. In myenteric plexus, many neurons had degenerated appearances and about 40% of them were lost. Most of ICC-Is had cytoplasmic vacuoles and 20~37% of the cells were lost. At 15 days after transection, there were no more degeneration in myenteric neurons (20~25% cell loss) and ICC-Is (20~13% cell loss). At 30 days after transection, numbers of myenteric neurons were not recovered as that of the control group. However numbers of ICC-Is were as similar as that of the control group. In conclusion, we confirmed that degeneration effects of intestinal transection are more severe in myenteric plexus than in ICC-Is, and recovery of cell loss occurs more slowly in myenteric plexus.