Ischemia-reperfusion injury and histamine release in isolated guinea-pig heart: the role of free radicals.

Free radicals produced by the occlusion and opening of the left anterior descending coronary artery and/or by perfusion of isolated guinea-pig heart with FeCl3/ADP (10 microM/100 microM) induce a differential release of histamine and lactate dehydrogenase (LDH) in the perfusates with a preferential liberation of histamine in the reperfusion phase, associated with an increase of ventricular arrhythmias. The release of histamine has been correlated with malonyldialdehyde (MDA) production and tissue calcium content in left ventricular tissue. MDA increased during ischemia, while the calcium content increased when the tissue was reperfused. Under these conditions, N-t-butyl-alpha-phenylnitrone (BPN), a molecule capable of forming spin adducts with free radicals, and D-mannitol are active in preventing reperfusion-induced arrhythmias.