Apocynin Exerts Dose-Dependent Cardioprotective Effects by Attenuating Reactive Oxygen Species in Ischemia/Reperfusion: A Recent Study | Chapter 2 | New Frontiers in Medicine and Medical Research Vol. 7
Because of increased reactive oxygen species and decreased endothelial-derived nitric oxide bioavailability, ischemia/reperfusion causes cardiac contractile failure and cell death. Endothelial dysfunction, which develops within 5 minutes of reperfusion, contributes to ischemia/reperfusion injury. Normally, NADPH oxidase creates reactive oxygen species to aid cell signalling and differentiation; however, excessive release of these species after ischemia exacerbates cell death. As a result, apocynin, a NADPH oxidase inhibitor, may help to preserve heart function and reduce infarct size after ischemia. Apocynin reduced leukocyte superoxide emission by 87 percent in a dose-dependent manner (40 (mu)M, 400 (mu)M, and 1 mM). After ischemia, isolated perfused hearts were given apocynin, which reduced infarct size to 39 7 percent (40 (mu)M), 28 4 percent (400 (mu)M; p 0.01), and 29 6 percent (1 mM; p 0.01), compared to 46 2 percent in the control group. This was linked to a reduction in final p...