Ischemia-reperfusion injury

Ischemia-reperfusion injury is tissue damage that occurs when blood flow returns after a period of restricted or absent circulation. Reintroduced oxygen and immune activity can worsen damage beyond that caused by ischemia alone.

Reactive oxygen species: Chemically reactive molecules derived from oxygen that can damage cellular components or participate in signaling. A rapid burst of these molecules after restored oxygen contributes to cellular damage.
Myocardial infarction: Death of heart muscle caused by prolonged inadequate blood supply, usually after a coronary artery becomes blocked. Opening the blocked artery saves heart muscle but can also cause reperfusion injury.
Ischemia: Inadequate blood flow to tissue, causing insufficient oxygen and nutrient delivery and impaired waste removal. It is the initial insult whose effects continue when circulation is restored.
Ischemic postconditioning: Brief interruptions of blood flow applied at the start of reperfusion to reduce tissue injury. Its proposed protective effects have not translated consistently across clinical settings.
Mitochondrial permeability transition pore: A stress-sensitive channel-like state of the inner mitochondrial membrane that collapses mitochondrial function when persistently open. Calcium overload and oxidative stress can open it, driving energy failure and cell death.
Ischemic stroke: Brain injury caused by blocked blood flow to part of the brain. Restoring flow can limit the original ischemia while exposing brain tissue to reperfusion damage.
Reperfusion: The restoration of blood flow to tissue after a period of reduced or absent circulation. It names the return of flow that can add damage to the preceding ischemia.
Therapeutic hypothermia: The controlled lowering of body or tissue temperature to reduce metabolic demand and injury. Cooling can limit injury in some contexts, but its role around reperfusion remains context-dependent.
Calcium overload: Excessive accumulation of calcium ions inside cells, disrupting normal cellular processes. Ischemic and reperfusion stress can produce calcium accumulation that destabilizes mitochondria.
Organ transplantation: The transfer of an organ from a donor to a recipient to replace a failing organ. A transplanted organ undergoes ischemia during preservation and reperfusion when circulation resumes.

Linked from 13 pages