Iron-catalyzed reactions cause lipid peroxidation in the intact heart.
The chemical targets and mechanisms of iron-catalyzed oxidative injury in myocardium are poorly understood. Oxygen metabolites, in the presence of iron, can initiate free-radical chain reactions in unsaturated membrane lipids, generating lipid peroxides and causing membrane injury. We examined whether exposure to iron-catalyzed oxidative injury would increase myocardial lipid peroxide levels as injury evolved in the intact heart. Isolated, buffer perfused rabbit hearts were exposed for 30 min to 100 uM Fe2+/500 uM ADP and 10 uM H2O2 (IRON group, n = 5), saline vehicle (CON group, n = 6) or 500 uM ADP and 10 uM H2O2 without iron (ADP, n = 5). Lipid peroxides were measured in cytosol and membrane fractions by a new method, using the lipid peroxide-induced oxidation of exogenous GSH to GSSG, catalyzed by the enzyme glutathione peroxidase. The results indicated that iron-catalyzed lipid peroxidation occurs in the intact heart during chemically-mediated oxidative injury.
Lesnefsky
E J
EJ
Case Western Reserve University, Cleveland, OH.
Allen
K G
KG
Carrea
F P
FP
Horwitz
L D
LD
D000818:Animals; D005978:Glutathione / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D007501:Iron / Q000378:metabolism* / Q000494:pharmacology; D015227:Lipid Peroxidation / Q000187:drug effects; D008054:Lipid Peroxides / Q000378:metabolism; D017202:Myocardial Ischemia / Q000378:metabolism; D015428:Myocardial Reperfusion Injury / Q000209:etiology / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D011817:Rabbits; D017382:Reactive Oxygen Species / Q000378:metabolism
D008054:Lipid Peroxides; D017382:Reactive Oxygen Species; D007501:Iron; D005978:Glutathione