Ischemia-Reperfusion Injury and free radicals Jianzhong Sheng Md PhD
Ischemia-Reperfusion Injury and Free Radicals Jianzhong Sheng MD PhD
History n 1955, Sewell et al reported that ventricular fibrillation occurred in dogs When sudden return of blood flow to the coronary artery that was ligated
• In 1955，Sewell et al., reported that ventricular fibrillation occurred in dogs when sudden return of blood flow to the coronary artery that was ligated History
Myocardial reperfusion injury was first postulated in 1960 by Jennings et al. in their description of the histologic features of reperfused ischemic canine myocardium The injury of ischemic cardiac muscles was more severe after reperfusion than before
• Myocardial reperfusion injury was first postulated in 1960 by Jennings et al. in their description of the histologic features of reperfused ischemic canine myocardium. The injury of ischemic cardiac muscles was more severe after reperfusion than before
1967, Bulkley and Hutchins found that reflow of blood induced necrosis of cardiac myocytes after coronary artery bypass graft surgery. 1981, Greenberg confirmed that reperfusion induced severe damage of the intestinal mucosal cells of cat after 3 hours of ischemia
• 1967，Bulkley and Hutchins found that reflow of blood induced necrosis of cardiac myocytes after coronary artery bypass graft surgery. • 1981, Greenberg confirmed that reperfusion induced severe damage of the intestinal mucosal cells of cat after 3 hours of ischemia
Clinice Shock, DIC microcirculation reperfusion Coronary reperfusion, artery bypass graft Restoration of blood supply in reimplantation of limb, transplantation of organs
Clinic: • Shock, DIC microcirculation reperfusion • Coronary reperfusion、artery bypass graft • Restoration of blood supply in reimplantation of limb, transplantation of organs
What is ischemia-reperfusion injury? The restoration of blood flow after transient ischemia may be associated with further reversible or irreversible cell damage, which is called ischemia-reperfusion injury or reperfusion injury
The restoration of blood flow after transient ischemia may be associated with further reversible or irreversible cell damage, which is called ischemia-reperfusion injury or reperfusion injury. What is ischemia-reperfusion injury?
In the definition of ischemia- reperfusion injury 3 Key points are: Ischemia for a long time Reestablishment of blood flow More severe injury
In the definition of ischemiareperfusion injury 3 Key points are: ➢ Ischemia for a long time ➢ Reestablishment of blood flow ➢ More severe injury
Characteristics of ischemia reperfusion injury 1. Reversible> Irreversible injury 2. Having reported in heart, kidney, liver, lung, brain intestine,, skeletal muscles Calcium paradox Oxygen paradox pH paradox
Characteristics of ischemiareperfusion injury: 1. Reversible → Irreversible injury 2. Having reported in heart, kidney, liver, lung, brain, intestine, skeletal muscles • Calcium paradox • Oxygen paradox • pH paradox
Etiology of ischemia-reperfusion Injury Cause 令令 schemia followed by reperfusion
Etiology of ischemia-reperfusion injury Cause Ischemia followed by reperfusion
Which factors are involved in reperfusion Generally speaking, 1. Duration of ischemia the longer period of ischemia, the more severe injury 2. Severity of ischemia the more grievous ischemia, the more severe injury 3. Speed of reperfusion the faster reperfusion of blood, the more severe injury 4. Ischemia preconditioning increasing tolerance to reperfusion injury
Which factors are involved in reperfusion Generally speaking, injury 1. Duration of ischemia the longer period of ischemia, the more severe injury 2. Severity of ischemia the more grievous ischemia, the more severe injury 3. Speed of reperfusion the faster reperfusion of blood, the more severe injury 4. Ischemia preconditioning increasing tolerance to reperfusion injury