Ischemia-Reperfusion Damage

The ischemia is the lack of oxygen due to the reduction or complete interruption in blood supply to the tissue. On the contrary, reperfusion is the process of restoring the blood flow to the ischemic tissue. However, sudden reperfusion of ischemic tissue paradoxically may result in much more severe damage to the tissue than ischemia-induced damage alone. Increased free oxygen radicals (SOR) are implicated in reperfusion injury. High amounts of molecular oxygen supplied to the ischemic tissue by fresh arterial blood are thought to have the potential to generate more SOR, eventually more tissue damage. Another source of SOR in the reperfusion is activated polymorph- nuclear leukocytes. The cyclooxygenase-2 (COX-2) enzyme becomes active in the reperfusion of ischemic tissue. This enzyme allows the pro-inflammatory prostaglandins and SORs to be released from arachidonic acid. Ischemic reperfusion is a complex pathological process that begins with oxygen-free ambient in tissue, continues with SOR production, and followed by an inflammation in tissue effected