title: Unique mode of cell death in freshly isolated adult rat ventricular cardiomyocytes exposed to hydrogen peroxide.
abstract: To address whether adult rat ventricular cardiomyocytes (ARVCs) exposed to oxidant stress die via apoptosis (secondarily by necrosis) or primarily by necrosis, we exposed ARVCs to hydrogen peroxide (H2O2; 0.1-100 microM) for up to 24 h and then compared them with isoproterenol-induced apoptotic and Triton X-induced necrotic controls. Cellular shrinkage preceded plasma membrane disruption, reflected by trypan blue uptake in ARVCs exposed to lower concentrations of H2O2 (<1 microM; an apoptotic pattern), but the order was reversed in cells exposed to higher concentrations of H2O2 (>1 microM; a necrotic pattern). DNA fragmentation, caspase-3 activation, mitochondrial membrane potential preservation, and ATP preservation were all apparent in ARVCs treated with low H2O2 (0.5 microM), but not in those treated with high H2O2 (10 microM). In addition, electron microscopy revealed unique morphology in H2O2-treated ARVCs; i.e., the nuclei had a homogeneous ground glass-like appearance that was never accompanied by chromatin condensation. Apparently, high concentrations of H2O2 caused primary necrosis in ARVCs, whereas low concentrations induced biochemically comparable apoptosis, although the latter did not satisfy the morphological criteria of apoptosis. These findings caution against the use of oxidant stress, H2O2 in particular, as an inducer of apoptosis in ARVCs.
authors.affiliation: Division of Cardiology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu, 501-1194, Japan.
authors.forename: Kazuko
authors.initials: K
authors.lastname: Goto
authors.forename: Genzou
authors.initials: G
authors.lastname: Takemura
authors.forename: Rumi
authors.initials: R
authors.lastname: Maruyama
authors.forename: Munehiro
authors.initials: M
authors.lastname: Nakagawa
authors.forename: Akiko
authors.initials: A
authors.lastname: Tsujimoto
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Kanamori
authors.forename: Longhu
authors.initials: L
authors.lastname: Li
authors.forename: Itta
authors.initials: I
authors.lastname: Kawamura
authors.forename: Tomonori
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Takeyama
authors.forename: Hisayoshi
authors.initials: H
authors.lastname: Fujiwara
authors.forename: Shinya
authors.initials: S
authors.lastname: Minatoguchi
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002478:Cells, Cultured; D053938:DNA Fragmentation; D006352:Heart Ventricles / Q000166:cytology; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008297:Male; D053078:Membrane Potential, Mitochondrial / Q000187:drug effects; D051336:Mitochondrial Membranes / Q000187:drug effects / Q000648:ultrastructure; D023421:Models, Animal; D032383:Myocytes, Cardiac / Q000166:cytology* / Q000187:drug effects / Q000648:ultrastructure; D009336:Necrosis; D016877:Oxidants / Q000494:pharmacology*; D018384:Oxidative Stress; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D016877:Oxidants; D000255:Adenosine Triphosphate; D006861:Hydrogen Peroxide; D053148:Caspase 3