![]() |
|
|
M Floreani and F Carpenedo
Department of Pharmacology, University of Padova, Italy.
In guinea pig and rat cardiac tissue, redox cycling benzoquinones (2,5- dimethyl-p-benzoquinone and duroquinone) and naphthoquinones (menadione and 2,3-dimethoxy-1,4-naphthoquinone) generated superoxide anion (O2-.) both through one- and two-electron reductions, the generation being significantly greater in guinea pig than in rat tissue. In electrically driven left atria isolated from guinea pig and rat, menadione and 2,5- dimethyl-p-benzoquinone but not duroquinone caused a concentration- dependent positive inotropic effect. Unlike guinea pig, 2,3-dimethoxy- 1,4-naphthoquinone had no effect in rat tissue. Naphthoquinones and 2,5- dimethyl-p-benzoquinone were more active in guinea pig than in rat tissue, their effect being dependent on the release of catecholamines from adrenergic stores. A linear relationship (r = 0.90) between the amount of O2-. generated by benzo- and naphthoquinones in guinea pig and rat heart and the extent of catecholamine-dependent positive inotropic effect was evident. An amount of O2-. higher than 600 nmol/g of tissue per min was calculated to be necessary to determine the catecholamine-mediated increase in contractility. Lipid peroxidation was not involved in quinone-induced catecholamine release.
This article has been cited by other articles:
![]() |
I. Valle, A. Alvarez-Barrientos, E. Arza, S. Lamas, and M. Monsalve PGC-1{alpha} regulates the mitochondrial antioxidant defense system in vascular endothelial cells Cardiovasc Res, June 1, 2005; 66(3): 562 - 573. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. H. Audi, R. D. Bongard, C. A. Dawson, D. Siegel, D. L. Roerig, and M. P. Merker Duroquinone reduction during passage through the pulmonary circulation Am J Physiol Lung Cell Mol Physiol, November 1, 2003; 285(5): L1116 - L1131. [Abstract] [Full Text] [PDF] |
||||