Angiotensin-conversing enzyme inhibition reduces lipid deposits in myocardium and improves left ventricular function of obese Zucker rats

TOBLLI JE; CAO G; DE ROSA G; DOMECQ P

OBESITY

NATURE PUBLISHING GROUP

Lugar: Londres; Año: 2006 vol. 14 p. 1586 - 1595

1930-7381

Abstract OBJECTIVE: Alterations in the renin angiotensin system, cardiac lipotoxicity, and left ventricular (LV) dysfunction have been reported in obese rats. The present study examined whether angiotensin-converting enzyme inhibition could ameliorate lipid deposition and ventricular function in the myocardium of obese Zucker rats (OZRs). RESEARCH METHODS AND PROCEDURES: For 6 months, rats were treated as follows: Group (G) 1, OZR, no treatment; G2, OZR + ramipril (R); G3, OZR + amlodipine (AML); and G4, lean Zucker rats. LV function was assessed by echocardiogram and lipid deposits in cardiomyocytes (LDCM) by light microscopy using Oil red O. RESULTS: At the end of the experiment, both OZR + R and OZR + AML groups presented similar reduction in blood pressure in comparison with untreated OZR (p < 0.01). OZR with R presented lower insulin-to-glucose ratio and lower serum triglycerides and cholesterol when compared with both untreated OZR and OZR with AML (p < 0.01). Fractional shortening by echocardiogram was as follows: G1, 25.4 +/- 3.8 (vs. G2 and G4, p < 0.05); G2, 37.2 +/- 2.4; G3, 29.3 +/- 4.4 (vs. G2 and G4, p < 0.05); and G4, 40.8 +/- 2.3. Percentage LDCM was as follows: G1, 12.4 +/- 2.7 (vs. G2 and G4, p < 0.05); G2, 0.8 +/- 0.2; G3, 11.1 +/- 2.1 (vs. G2 and G4, p < 0.05); and G4, 0.1 +/- 0.1. There was a negative correlation between fractional shortening and LDCM percentage in OZR (r = -0.93) and in OZR + AML (r = -0.87). DISCUSSION: AML reduced blood pressure significantly; however, it failed to modify both metabolic parameters and LDCM. In contrast, R showed a substantial reduction in LDCM, together with LV function preservation.