What is reoxygenation injury?

Reperfusion injury, sometimes called ischemia-reperfusion injury (IRI) or reoxygenation injury, is the tissue damage caused when blood supply returns to tissue (re- + perfusion) after a period of ischemia or lack of oxygen (anoxia or hypoxia).

How does reoxygenation work?

Reoxygenation refers to the empirical observation that hypoxic regions in tumors may improve their oxygenation during fractionated radiotherapy.

How hypoxia causes cell injury?

During hypoxic injury blood flow falls below a certain critical level that is required to maintain cell viability. The interrupted supply of oxygenated blood to cells results in anaerobic metabolism and loss of adenosine triphosphate (ATP), and cellular membrane disruption (see Figure 1).

What does hypoxia do to cells?

Mitochondria act as signaling organelles in low-oxygen conditions. Hypoxia (0.5–3% oxygen) increases mitochondrial ROS that activate transcription of adaptive genes. Anoxia (0–0.5% oxygen) initiates mitochondrial outer membrane permeabilization (MOMP) to activate cell death.

What are the factors that affect Reoxygenation?

These include the increases in hypoxia inducible factor, vascular endothelial growth factor, nitric oxide, and the activation of protein kinase C, nuclear factor-κβ, adenylate cyclase, and intracellular calcium pathways.

What is the meaning of Reoxygenation?

Reoxygenation is the phenomenon where cells that are hypoxic at the time of irradiation become oxygenated after irradiation. The rapid reoxygenation is attributable to effects on acutely hypoxic cells, the “slow” reoxygenation being attributable to effects on chronically hypoxic cells.

Which cell is most sensitive to hypoxia?

CNS Pathology. The neurons are the most sensitive cells to anoxic injury. Seen here are red neurons which are dying as a result of hypoxia. One of the most sensitive areas in the brain to hypoxic injury is the hippocampus, as seen below.

How is reperfusion syndrome treated?

Potential therapies include pharmacological treatment, ischemic preconditioning, and the use of medical gases or vitamin therapy, which could significantly help experts develop strategies to inhibit ischemia reperfusion injury.