Ischemia-reperfusion injury is associated with which phenomenon during reperfusion?

Prepare for the Tissue Injury, Healing, and Pain Test. Utilize flashcards and multiple-choice questions with hints and explanations. Ensure you're ready for the exam!

During reperfusion, a sudden influx of oxygen triggers a burst of reactive oxygen species, leading to oxidative stress and inflammation. Ischemia leaves cellular systems damaged and accumulates substrates like hypoxanthine; when oxygen floods in, xanthine oxidase and mitochondrial electron transport chains generate large amounts of ROS such as superoxide. These reactive species oxidize lipids, proteins, and DNA, disrupt membranes, and promote mitochondrial permeability transition, calcium overload, and further cell injury. The oxidative damage also activates inflammatory pathways, drawing neutrophils to the site and triggering cytokine release and adhesion molecule expression, which amplifies tissue injury. So the key phenomenon during reperfusion is this ROS burst driving oxidative stress and inflammation. Neutrophil apoptosis isn’t the main driver, reduced inflammation would lessen injury, and simply delivering oxygen isn’t the direct injurious trigger—the ROS generated upon reoxygenation is.