Lipid Peroxidation and Reperfusion Injury in Hypertrophied Hearts

FANTINELLI JC; PÉREZ NÚÑEZ IA; GONZÁLEZ ARBELÁEZ LF; MOSCA SM

Lipid Peroxidation

Intech

Año: 2012; p. 393 - 408

Oxidative stress is characterized by an imbalance between increased exposure to reactiveoxygen species (ROS), and antioxidant defenses, comprised of both small molecular weightantioxidants like glutathione, and antioxidant enzymes like superoxide dismutase. ROScause direct damage to critical biomolecules including DNA, lipids, and proteins. Oxidativestress has been involved in the genesis of hypertension [1, 2] and implicated in themechanisms of reversible postischemic contractile dysfunction (myocardial stunning),microvascular dysfunction, arrhythmias and cell death [3-6]. In spontaneously hypertensiverats (SHR) there are few reports showing the protective action of antioxidants againstischemia-reperfusion injury [7-9] and specifically in regard to the effects of the scavenger N-(2-mercaptopropionyl)-glycine (MPG) these have not been yet examined.Ischemic preconditioning (IP) is acknowledged to be an endogenous mechanism ofcardioprotection against ischemia and reperfusion injury [10-11]. This intervention is basedin that one or more brief periods of ischemia applied previous to a prolonged ischemicperiod exert beneficial effects on myocardium attenuating the deleterious effects observed inthe reperfused myocardium. Although there are some studies showing the beneficial effectsof IP in hypertensive animals [12-15], under certain circumstances the effectiveness of thatintervention is questioned [16-18]. A recent investigation performed in our laboratory showsthat a single cycle of IP attenuated the myocardial stunning produced by 20-min globalischemia in SHR [19] and decreased the lipid peroxidation. Whether this protective action ofIP is operating at more extended ischemic period and involves changes in oxidative stress inthis rats strain is a point that needs to be clarified.Therefore, the aim of the present study was to determine if alterations of lipid peroxidationand endogenous antioxidants are linked to myocardial and vascular postischemic damagein ischemic control, preconditioned and MPG treated hearts from SHR.