Flashcards in Chap 7 Ischemia Reperfusion Deck (12):
What is the main cause of injury during ischemia?
From hypoxia/anoxia and stasis in microcirculation
Describe how ischemic injury occurs.
Mitochondria without O2 cannot produce ATP by oxidative phosphorylation
ATP falls, with ADP and AMP rise.
Glycolysis stimulated but insufficient for the cell
Lactic acid builds up making intracellular pH decrease, this then inhibits glycolysis
To compensate ion pumps are supposed to pump H ions out however there is pump dysfunction as no O2. Intracellular Ca rises are a consequence
This leads to eventually cell memebrane damage and cell death
During process reactive O2 species produced and accum in mitochondria
Increase ROS and Ca causes cell necrosis
What are the main causes of injury during reperfusion?
Metabolic, thrombotic, inflammatory
Describe reperfusion injury.
Burst of ROS production, increased Ca uptake into mito, shift of pH towards enutral
Mitochondrial oxidative damage leads to cell death through apoptosis and necrosis
Increased ROS during ischemia and reperfusion initiated apptosis and necrosis
Elicits inflamm response dependent of complement
Imflamm mediators delivered to reperfused tissue (mac, lumphocytes, neutrophils, mast cells and plt)
List clinical manifestations of reperfusion injury.
no reflow phenomena
Describe myocardial stunning.
Reversible, decreased ATP resunthesis, coronary spasm, cytotoxic injury
Rapid and sudden changes in ions concentration
Describe tissue edema.
Disruption to blood brain barrier can cause increased ICP
Which organ most injured in multi-organ dysfunction.
Lungs most frequently injured
How long before nerve ischemia is permanent in CS.
What causes bacterial translocation.
increased intestinal permeability.