[Hydrogen peroxide augments the injury effect of iron on the isolated rat heart and cardiomyocytes].
By using Langendorff perfused rat heart and enzymatically isolated cardiomyocytes, we investigated the augmented injury effect of iron on the myocardium by hydrogen peroxide and the underlying mechanisms. Cell-permeable iron (Fe-HQ) decreased the contractile amplitude, velocity and end-diastolic cell length of the cardiomyocyte but increased the contents of lactate dehydrogenase (LDH) and creatine kinase (CK) in the coronary effluent and the myocardial malondialdehyde (MDA) while the left ventricular developed pressure (LVDP), +/-dp/dt(max), heart rate and coronary flow showed biphasic alterations. Hydrogen peroxide augmented the injury effect of iron accompanied by increases of coronary LDH, CK release and myocardial MDA content and decreases of LVDP, +/-dp/dt(max), and heart rate. Reduced glutathione could antagonize the injury effect of iron and hydrogen peroxide on the myocardium while dimethyl sulfoxide had no injury effect on the isolated heart. It is suggested that the functional injury of sulfhydryl group containing proteins may be involved in the augmentation of myocardial injury due to the increase of intracellular iron by hydrogen peroxide, but hydroxyl radicals may not.
Chen
Y Y
YY
Department of Physiology, Zhejiang University School of Medicine, 310006, Hong Kong.
Shen
Y L
YL
Cao
C M
CM
Xu
W H
WH
Qian
Z M
ZM
Xia
Q
Q
D000818:Animals; D001693:Biological Transport, Active; D006321:Heart / Q000503:physiopathology*; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D066298:In Vitro Techniques; D007501:Iron / Q000494:pharmacology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D032383:Myocytes, Cardiac / Q000378:metabolism / Q000473:pathology*; D015125:Oxyquinoline / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D015125:Oxyquinoline; D006861:Hydrogen Peroxide; D007501:Iron; D007770:L-Lactate Dehydrogenase