During hypoxia, there is a third-stage obstacle to oxygen oxidation. During reperfusion, oxygen undergoes single-electron reduction to generate an increase in reactive oxygen species.

Chemokines can be produced during hypoxia to attract and activate neutrophils. During reperfusion, activated neutrophils consume more oxygen and produce a large amount of oxygen free radicals.

Ca-dependent proteolytic enzyme converts XD to XO

A large amount of hypoxanthine accumulates in ischemic tissue. During reperfusion, oxygen oxidizes hypoxanthine under the action of xanthine oxidase to generate uric acid and H₂O₂, resulting in a large increase in reactive oxygen species.

The stress reaction produces a large amount of catecholamines and a large amount of oxygen free radicals through self-oxidation.

Destruction of cell and organelle membrane structures

Increased production of biologically active substances

Reduced ATP production

Na-Ca2 exchanger antiporter

Acts on α₁-R to promote the decomposition of PIP₂ to form IP₃ and DG

Acts on β-R, activates CA, increases the opening of calcium channels, and promotes the influx of calcium ions

cell membrane damage

mitochondrial membrane damage

endoplasmic reticulum membrane damage

Mitochondria absorb Ca2, which consumes energy. After entering the mitochondria, calcium phosphate is formed, causing mitochondrial dysfunction and reduced ATP production.

Activate phospholipases to promote membrane phospholipid degradation

Activates calcineurin to promote the breakdown of cell membrane and structural proteins

Activates endonucleases, causing chromosomal damage

Opens the mitochondrial permeability transduction pore, inhibits respiratory function and promotes the release of cytochrome C, promoting cell apoptosis.

Enhanced anaerobic glycolysis and increased lactic acid

High intracellular calcium activates certain ATPases, hydrolyzes high-energy phosphates, and releases H

Microvascular hemorrheological changes

Increased microvascular permeability

Heterogeneity of action potential duration between reperfused myocardium

Cardiomyocyte calcium overload

Increased free radicals and reactive oxygen species

Increased endogenous catecholamines

myocardial stunning

Hardly used clinically

Heart and brain unavailable

Wide range of clinical applications