| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Department of Medicine, Division of Cardiology, University of British Columbia, Vancouver, British Columbia V5Z 3J5, Canada
We examined
the hypothesis that sodium nitroprusside (SNP) produces cell death in
cardiomyocytes through generation of H2O2. Embryonic chick cardiomyocytes in culture were treated with SNP, and
cell viability was assessed by trypan blue, MTT assay, and fluorescent
activated cell sorting (FACS) analysis. SNP for 24 h
induced a significant (P < 0.001) dose-dependent loss of
cell viability. On MTT assay, the half-maximal effective concentration was 0.53 mM (confidence interval 0.45-0.59 mM).
SNP-treated cardiomyocytes displayed characteristic microscopic
features of apoptosis: reduced cell size, nuclear disintegration, and
membrane bleb formation. FACS analysis demonstrated SNP-induced
apoptosis as well as cell changes consistent with necrosis. The
proportion of cells with nuclear changes of apoptosis, identified by
propidium iodide (PI) staining of permeabilized cells, increased
significantly (P < 0.05) after 0.5 mM SNP for 24 h.
The proportion of apoptotic cells, characterized by dual staining of
intact cardiomyocytes with fluorescein diacetate and PI, was
significantly (P < 0.05) increased after treatment with 0.5 mM SNP for 24 h. SNP metabolism and NO production was suggested by
the significant (P < 0.05) increase in nitrite generation
in the media with 0.5 mM SNP compared with control. SNP-mediated
H2O2 production was implicated in the mechanism
of SNP-induced cell death. First, SNP produced a significant (P
< 0.05) increase in H2O2 detected in the
media after 6 or 24 h of SNP treatment. Second, catalase
completely blocked the reduction of cell viability induced by 0.1 mM
SNP and significantly (P < 0.05) blunted the effect of
0.5 mM SNP. In contrast, the iron chelator deferoxamine did not
alter SNP-induced loss of cell viability. FACS analysis showed that the
combination of low concentrations of H2O2
(10
8 M) that did not alter cell viability augmented
SNP-induced apoptosis. In contrast, the amount of necrotic cell death
was unchanged by the combination of H2O2 and
SNP. H2O2 plus SNP produced a dramatic alteration in cell structure with greater membrane bleb formation, shrunken cells, and more intense cytosolic acridine orange staining and
nuclear fragmentation than either agent alone. These data indicate the
vulnerability of cardiomyocytes to SNP and suggest the involvement of
H2O2 in the pathogenesis of SNP-induced
cardiomyocyte cell death. Establishing apoptosis as a component of the
type of cell death induced by SNP permitted the recognition that
SNP-induced apoptosis was increased by chronic treatment with low
(subtoxic) concentrations of H2O2.
apoptosis
This article has been cited by other articles:
|
|
 |
|
  M. Luong and S. Rabkin Verapamil but not calpain or creatine alters arsenate-induced cardiac cell death Toxicology and Industrial Health, April 1, 2009; 25(3): 169 - 176. [Abstract] [PDF]
|
|
|
|
 |
|
 S. Cardaci, G. Filomeni, G. Rotilio, and M. R. Ciriolo Reactive Oxygen Species Mediate p53 Activation and Apoptosis Induced by Sodium Nitroprusside in SH-SY5Y Cells Mol. Pharmacol., November 1, 2008; 74(5): 1234 - 1245. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. W. Rabkin and M. Y. C. Tsang The action of nitric oxide to enhance cell survival in chick cardiomyocytes is mediated through a cGMP and ERK1/2 pathway while p38 mitogen-activated protein kinase-dependent pathways do not alter cell death Exp Physiol, July 1, 2008; 93(7): 834 - 842. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 U. Rauen, T. Li, I. Ioannidis, and H. de Groot Nitric oxide increases toxicity of hydrogen peroxide against rat liver endothelial cells and hepatocytes by inhibition of hydrogen peroxide degradation Am J Physiol Cell Physiol, April 1, 2007; 292(4): C1440 - C1449. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. M. Tiwari, K. J. Messer, and P. R. Mayeux Inducible Nitric Oxide Synthase and Apoptosis in Murine Proximal Tubule Epithelial Cells Toxicol. Sci., June 1, 2006; 91(2): 493 - 500. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 T. Shokoji, Y. Fujisawa, S. Kimura, M. Rahman, H. Kiyomoto, K. Matsubara, K. Moriwaki, Y. Aki, A. Miyatake, M. Kohno, et al. Effects of Local Administrations of Tempol and Diethyldithio-Carbamic on Peripheral Nerve Activity Hypertension, August 1, 2004; 44(2): 236 - 243. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 F. Eefting, B. Rensing, J. Wigman, W. J. Pannekoek, W. M. Liu, M. J. Cramer, D. J Lips, and P. A Doevendans Role of apoptosis in reperfusion injury Cardiovasc Res, February 15, 2004; 61(3): 414 - 426. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. V. Remillard and J. X.-J. Yuan Activation of K+ channels: an essential pathway in programmed cell death Am J Physiol Lung Cell Mol Physiol, January 1, 2004; 286(1): L49 - L67. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Y. Kong and S. W. Rabkin Palmitate-induced cardiac apoptosis is mediated through CPT-1 but not influenced by glucose and insulin Am J Physiol Heart Circ Physiol, February 1, 2002; 282(2): H717 - H725. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
