Attenuation of oxidant stress during reoxygenation by AMP 579 in cardiomyocytes.

Abstract

AMP 579, an adenosine A(1)/A(2) receptor agonist, has a strong anti-infarct effect when administered just before reperfusion. Because oxidative stress has been proposed to contribute to myocardial reperfusion injury, we tested whether AMP 579 can reduce the production of reactive oxidant species (ROS) during reoxygenation in cultured chick embryonic cardiomyocytes. The intracellular fluorescent probe 2',7'-dichlorofluorescin diacetate (DCFH) was used to detect ROS. The cells were subjected to 60 min of simulated ischemia, followed by either 15 min or 3 h of reoxygenation. AMP 579 (0.5 and 1 microM), when started 10 min before reoxygenation, significantly reduced ROS generation from 4.86 +/- 0.30 (arbitrary units) in untreated cells to 2.72 +/- 0.31 and 1.85 +/- 0.14, respectively (P < 0.05). Cell death that was assessed by propidium iodide uptake was markedly reduced by AMP 579 (49.6 +/- 4.7% of control cells vs. 25.4 +/- 2.4%, P < 0.05). In contrast, adenosine did not alter ROS generation or cell death. Attenuation of ROS production by AMP 579 was completely prevented by simultaneous exposure of cells to the selective adenosine A(2) antagonist 8-(13-chlorostyryl) caffeine. These results indicate that AMP 579 directly protects cardiomyocytes from reperfusion injury by a mechanism that attenuates intracellular oxidant stress. Furthermore, adenosine could not duplicate these effects.

• Authors: Z Xu, M V Cohen, J M Downey, T L Vanden Hoek, Z Yao
• Journal: American journal of physiology. Heart and circulatory physiology (Am J Physiol Heart Circ Physiol) Vol. 281 Issue 6 Pg. H2585-9 (Dec 2001) ISSN: 0363-6135 [Print] United States
• PMID: 11709426 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• 4-(7-((2-3-chloro-2-thienyl)-1-methyl-propylamino)-3H-imidazo(4,5-b)pyridyl-3-yl)cyclopentane carboxamide
• Imidazoles
• Pyridines
• Reactive Oxygen Species
• Adenosine

Topics

• Adenosine (metabolism)
• Animals
• Cell Survival (drug effects, physiology)
• Cells, Cultured
• Chick Embryo
• Imidazoles (pharmacology)
• Muscle Fibers, Skeletal (cytology, metabolism)
• Myocardial Reperfusion Injury (metabolism)
• Myocardium (cytology, metabolism)
• Oxidative Stress (drug effects, physiology)
• Pyridines (pharmacology)
• Reactive Oxygen Species (metabolism)