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Ischemic postconditioning reduces infarct size by activation of A1 receptors and K+(ATP) channels in both normal and hypercholesterolemic rabbits.
- Source :
-
Journal of cardiovascular pharmacology [J Cardiovasc Pharmacol] 2007 May; Vol. 49 (5), pp. 287-92. - Publication Year :
- 2007
-
Abstract
- The effect of ischemic postconditioning (Postcon) in hypercholesterolemic animals is unknown. The objectives were to determine if ischemic preconditioning (IPC) and Postcon reduce infarct size in hypercholesterolemic animals and to assess if A1 receptors and K+(ATP) channels are involved in Postcon mechanisms. Isolated rabbit hearts were perfused according to the Langendorff technique and subjected to 30 minutes of ischemia and 30 minutes of reperfusion (G1). In Group 2, IPC was performed (1 cycle of 5 minutes ischemia/reperfusion) before 30 minutes of ischemia. In Group 3 (G3), Postcon was performed (2 cycles of 30-second reperfusion/ischemia) after 30 minutes of ischemia. The G3 protocol was repeated in G4 and G5, but during Postcon, an A1 receptor blocker (DPCPX, 200 nM) and glybenclamide (K+(ATP), blocker, 0.3 microM) were administered, respectively. The G1 to G5 protocols were repeated in animals fed with an enriched cholesterol diet (1%) for 4 weeks (G6 to G10). The infarct size was measured by triphenyltetrazolium. The infarct size was 16.6 +/- 4.6% in G1 and 25.8 +/- 7.3% in G6, and IPC and Postcon reduced the infarct area in both normal and hypercholesterolemic animals (G2: 5.1 +/- 1.7% [P < 0.05] and G3: 5.4 +/- 0.9% [P < 0.05] in normal animals; G7: 4.1 +/- 1.6% [P < 0.05] and G8 4.8 +/- 0.9% [P < 0.05], in hypercholesterolemic animals). Both DPCPX and glybenclamide abolished the effect reached by Postcon. Thus, Postcon reduces infarct size in normal and hypercholesterolemic animals through the activation of A1 and K+(ATP) channels.
- Subjects :
- Analysis of Variance
Animals
Anti-Arrhythmia Agents pharmacology
Coronary Circulation drug effects
Disease Models, Animal
Endothelium, Vascular metabolism
Endothelium, Vascular physiopathology
Glyburide pharmacology
Hypercholesterolemia complications
Hypercholesterolemia pathology
Hypercholesterolemia physiopathology
Ischemic Preconditioning, Myocardial
Myocardial Contraction drug effects
Myocardial Infarction etiology
Myocardial Infarction physiopathology
Myocardial Infarction prevention & control
Myocardial Reperfusion Injury complications
Myocardial Reperfusion Injury pathology
Myocardial Reperfusion Injury physiopathology
Myocardial Reperfusion Injury prevention & control
Potassium Channel Blockers pharmacology
Rabbits
Ventricular Pressure drug effects
Xanthines pharmacology
Adenosine A1 Receptor Antagonists
Hypercholesterolemia metabolism
Myocardial Infarction metabolism
Myocardial Infarction pathology
Myocardial Reperfusion Injury metabolism
Potassium Channels drug effects
Potassium Channels metabolism
Receptor, Adenosine A1 metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0160-2446
- Volume :
- 49
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- Journal of cardiovascular pharmacology
- Publication Type :
- Academic Journal
- Accession number :
- 17513947
- Full Text :
- https://doi.org/10.1097/FJC.0b013e31803c55fe