ave-0991 and Myocardial-Infarction

Topics: Animals; Captopril; Imidazoles; Losartan; Myocardial Infarction; Myocardial Reperfusion Injury; Rats; Receptor, Angiotensin, Type 2; Sulfonamides; Thiophenes

We evaluated effects of the nonpeptide angiotensin (ANG)-(1-7) analog AVE 0991 (AVE) on cardiac function and remodeling as well as transforming growth factor-beta1 (TGF-β1)/tumor necrosis factor-alpha (TNF-α) expression in myocardial infarction rat models.. Sprague-Dawley rats underwent either sham surgery or coronary ligation. They were divided into four groups: sham, control, AVE, and AVE+A-779 [[D-Ala(7) ]-ANG-(1-7), a selective antagonist for the ANG-(1-7)] group. After 4 weeks of treatment, the AVE group displayed a significant elevation in left ventricular fractional shorting (LVFS) (25.5 ± 7.3% vs. 18.4 ± 3.3%, P < 0.05) and left ventricular ejection fraction (LVEF) (44.8 ± 7.6% vs. 32.7 ± 6.5%, P < 0.05) when compared to the control group, but no effects on the left ventricular end-diastolic and end-systolic diameters (LVDd and LVDs, respectively) were observed. In addition, we found that the myocyte diameter (18 ± 2 μm vs. 22 ± 4 μm, P < 0.05), infarct size (42.6 ± 3.6% vs. 50.9 ± 4.4%, P < 0.001) and collagen volume fraction (CVF) (16.4 ± 2.2% vs. 25.3 ± 3.2%, P < 0.001) were significantly reduced in the AVE group when compared to the control group. There were no differences in LVFS, LVEF, myocyte diameter, and infarct size between the control and AVE+A-779 groups. AVE also markedly attenuated the increased mRNA expression of collagen I (P < 0.001) and collagen III (P < 0.001) and inhibited the overexpression of TGF-β1 (P < 0.05) and TNF-α (P < 0.05) compared to the control group.. AVE could improve cardiac function and attenuate ventricular remodeling in MI rat models. It may involve the inhibition of inflammatory factors TGF-β1/TNF-α overexpression and the action on the specific receptor Mas of ANG-(1-7).

Topics: Angiotensin II; Animals; Cardiomegaly; Cardiotonic Agents; Collagen; Disease Models, Animal; Hemodynamics; Imidazoles; Male; Myocardial Contraction; Myocardial Infarction; Myocardium; Peptide Fragments; Proto-Oncogene Mas; Proto-Oncogene Proteins; Rats; Rats, Sprague-Dawley; Receptors, G-Protein-Coupled; Signal Transduction; Stroke Volume; Transforming Growth Factor beta1; Tumor Necrosis Factor-alpha; Ventricular Function, Left; Ventricular Remodeling

The nonpeptide AVE-0991, which has been reported as a selective ligand for the angiotensin-(1-7) [ANG-(1-7)] receptor Mas, has actions similar to those attributed to the cardioprotective product of the renin-angiotensin system, ANG-(1-7). In this study, we evaluated the cardiac effects of AVE-0991 in normal and infarcted male Wistar rats. Myocardial infarction was induced by left coronary artery ligation. At the end of the treatment, the Langendorff technique was used to analyze cardiac function. Left ventricle serial sections were dyed with Gomori trichrome stain to quantify the infarcted area. In normal hearts, AVE-0991 produced a significant decrease in perfusion pressure and an increase in systolic tension, rate of tension rise and fall (+/-dT/dt), and heart rate. These effects were completely blocked by the perfusion of the hearts with a solution containing the selective ANG-(1-7) antagonist A-779. N(G)-nitro-l-arginine methyl ester treatment abolished the AVE-0991-induced vasodilation in isolated hearts. AVE-0991 significantly attenuated the decrease in systolic tension (sham operated, 13.00 +/- 1.02 g; infarction, 7.18 +/- 0.66 g; AVE treated, 9.23 +/- 1.05 g, n = 5), +dT/dt, -dT/dt, and heart rate induced by myocardial infarction. Infarction-induced vasoconstriction was completely prevented by AVE-0991 treatment. Furthermore, AVE-0991 significantly decreased the infarcted area (6.98 +/- 1.01 vs. 3.94 +/- 1.04 mm(2) in AVE-treated rats). These data indicate that the compound AVE-0991 produces beneficial effects in isolated perfused rat hearts involving the ANG-(1-7) receptor Mas and the release of nitric oxide. In addition, our results indicate that AVE-0991 attenuates postischemic heart failure.

Topics: Angiotensin II; Animals; Cardiac Output, Low; Coronary Vessels; Disease Models, Animal; Enzyme Inhibitors; Heart Rate; Heart Ventricles; Imidazoles; Ligation; Male; Myocardial Infarction; NG-Nitroarginine Methyl Ester; Nitric Oxide; Nitric Oxide Synthase; Peptide Fragments; Proto-Oncogene Mas; Proto-Oncogene Proteins; Rats; Rats, Wistar; Receptors, G-Protein-Coupled; Time Factors; Vasoconstriction; Vasodilator Agents; Ventricular Function, Left