Apoptosis of interstitial cells of Cajal, smooth muscle cells, and enteric neurons induced by intestinal ischemia and reperfusion injury in adult guinea pigs

This study aimed at evaluating whether apoptosis of interstitial cells of Cajal (ICC), smooth muscle cells (SMC), and enteric neurons was involved in a guinea pig model of intestinal ischemia and reperfusion injury. The small intestinal segments were resected at either 6 (I-60/R-6h) and 12 h (I-60/R-12h) or 7 (I-60/R-7d) to 14 (I-60/R-14d) days after 60 min intestinal ischemia in the adult guinea pigs and studied by immunohistochemistry with anti-Kit, 5-bromo-2'-deoxyuridine (BrdU), alpha-smooth muscle actin, vimentin, and beta-tublin III antibodies. Also, apoptosis was tested by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) method. In the I-60/R-12h injury, there was a similar to 50% decrease of Kit+ cells in cell numbers at the level of myenteric plexus and a number of Kit-/vimentin-positive cells were labeled by TUNEL. Also, a few SMC and enteric neurons were TUNEL positive. The Kit+ ICC recovered to normal and a number of Kit-/BrdU-double-positive cells were observed in the I-60/R-14d group. Our results indicated that the intestinal I/R injury could lead to apoptosis of ICC, SMC, and enteric neurons which may contribute to the gastrointestinal motility disorders, and proliferation was involved in the recovery of ICC.