INTESTINAL MICROCIRCULATION AND LEUKOCYTE BEHAVIOR IN ISCHEMIA-REPERFUSION INJURY

Polymorphonuclear leukocytes are thought to play a pivotal role in the generation of ischemia-reperfusion-induced mucosal injury; however, t heir behavior in the intestinal microvasculature following this injury has not been directly examined. In this study intravital microscopy w as used to investigate the dynamics of blood how and leukocyte behavio r in the villus, serosal, and mesenteric microcirculation during ische mia-reperfusion in anesthetized hamsters. Thirty minutes of ischemia a nd 90 min of reperfusion resulted in almost complete microvascular sta sis in the villi of control animals, whereas only a few serosal and me senteric microvessels exhibited stasis. Following reperfusion, there w as a significant increase in leukocyte accumulation in all three tissu es; however, significantly fewer leukocytes adhered in the villus micr ovasculature than in the rest of either the mucosa, serosa, or mesente ry. Treatment with gamma-hydroxybutyrate (GHB), a compound that we hav e previously demonstrated to be highly effective in preventing ischemi a-reperfusion injury, significantly reduced both the microvascular sta sis and leukocyte accumulation in all three vascular beds. This study demonstrates that there are significant differences in the response to ischemia-reperfusion in various intestinal layers and that areas most susceptible to damage are not necessarily those exhibiting the greate st leukocyte accumulation. (C) 1994 Academic Press, Inc.