Intracellular pH and Ca2+ homeostasis in the pH paradox of reperfusion injury to neonatal rat cardiac myocytes

Reperfusion of ischemic myocardium, resulting in reoxygenation and reattainment of physiological pH levels, is attributed to intracellular pH and cytosolic free calcium (Ca2+), as observed in cardiac myocytes from neonated rats. Cellular injury is enhanced and the onset of tissue necrosis is triggered by reperfusion, prior to a crucial phase of ischemia. Artificially induced ischemia by pretreatment of myocytes with a contribution of 20mM 2-deoxyglucose and 2.5mM sodium cyanide (NaCN) exhibits a decrease in pH value, which attains a constant value below a pH of 6.2 and is accompanied by hypercontraction and little blebbing.