ischemia reperfusion injury

Description

Adverse functional, metabolic, or structural changes in ischemic tissues resulting from the restoration of blood flow to the tissue (reperfusion), including swelling; hemorrhage; necrosis; and damage from free radicals. The most common instance is myocardial reperfusion injury.; Some of the known risk factors for cardiovascular disease (hypercholesterolaemia, hypertension, and diabetes) appear to exaggerate many of the microvascular alterations elicited by ischaemia and reperfusion (I/R). The inflammatory mediators released as a consequence of reperfusion also appear to activate endothelial cells in remote organs that are not exposed to the initial ischaemic insult. This distant response to I/R can result in leukocyte-dependent microvascular injury that is characteristic of the multiple organ dysfunction syndrome. Adaptational responses to I/R injury have been demonstrated that allow for protection of briefly ischaemic tissues against the harmful effects of subsequent, prolonged ischaemia, a phenomenon called ischaemic preconditioning.