Expression of adhesion molecules and leukocyte recruitment into gastric mucosa following ischemia-reperfusion

Leukocyte infiltration is an important step in postischemic tissue damage. This study aimed to determine the expression of adhesion molecules and their relationship with leukocyte infiltration in the postischemic gastric mucosa. Gastric tissue was obtained from rats subjected to 30 min gastric ischemia followed by reperfusion. Sections were stained with specific antibodies against (1) L-selectin and (2) LFA-1 on leukocytes, (3) ICAM-1 on endothelial cells, (4) PMNs, and (5) monocytes. Stained cells or blood vessels in mucosal tissue were counted using image analysis. Results showed that from 5 min of reperfusion, numbers of L-selectin-positive cells decreased, whereas LFA-1-positive cells and PMNs increased compared with controls. ICAM-1 expression did not increase until 60 min of reperfusion. Monocyte numbers were unaffected by reperfusion. We conclude that gastric ischemia-reperfusion results in a rapid influx of LFA-1-positive cells, the majority of which are PMN. L-Selectin is shed from these cells allowing them to adhere to the microvasculature via constitutively expressed ICAM-1.