Impaired Intestinal Mucosal Barrier upon Ischemia-Reperfusion: “Patching Holes in the Shield with a Simple Surgical Method”
Figure 3
Representative photographs of claudin-2, claudin-3, claudin-4, and zonula occludens-1 immunostained in longitudinal jejunal sections of the three experimental groups. Claudin-2 immunoreaction in the sham-operated group (a) was low and was mainly found in the cytoplasm of the intestinal epithelial cells. Claudin-2 expression in the groups exposed to ischemia-reperfusion was substantially higher and was principally found in the lateral membrane of the epithelial cells (b, c). The sham-operated group presented strong membrane claudin-3 immunostaining (d), which was remarkably decreased in the ischemia-reperfusion- (IR-) group (e), but not in the postconditioned- (PC-) group (f). Minimal claudin-4 immunostaining was observed in the jejunal samples of the sham-operated animals (g). The two groups challenged with 60 minutes of mesenteric ischemia and 6 hours of reperfusion (h, i) showed high membrane claudin-4 expression, which was limited to the tips of the villi. Zonula occludens-1 was strongly immunostained in the jejunal samples of the sham-operated animals (j). Following small intestinal ischemia-reperfusion, intestinal epithelial cell with zonula occludens-1 membrane immunostaining notably decreased in the IR-group (k); in the PC-group minimal loss of zonula occludens-1 membrane immunostaining was detected (l). Each photograph was taken with the same magnification. Scale bar: 20 μm.
