ISCHEMIA-REPERFUSION INJURY TO THE INTESTINE

Ischaemia-reperfusion injury (IRI) is of obvious relevance in situatio ns where there is an interruption of blood supply to the gut, as in va scular surgery, or in the construction of free intestinal grafts. It i s now appreciated that IRI also underlies the gut dysfunction that occ urs in early shock, sepsis, and trauma. The events that occur during I RI are complex. However, recent advances in cellular biology have star ted to unravel these underlying processes. The aim of this review is t o provide an outline of current knowledge on the mechanisms and conseq uences of IRI. Initially, IRI appears to be mediated by reactive oxyge n metabolites and, at a later stage, by the priming, and activation of poly morphonuclear neutrophils (PMN). Ischaemia-reperfusion injury ca n diminish the barrier function of the gut, and can promote an increas e in the leakage of molecules (intestinal permeability) or the passage of microbes across the wall of the bowel (bacterial translocation). I schaemia-reperfusion injury to the gut can result in the generation of molecules that may also harm distant tissues.