CENTRO DE INVESTIGACIONES CARDIOVASCULARES "DR. HORACIO EUGENIO CINGOLANI"
Unidad Ejecutora - UE
congresos y reuniones científicas
EXERCISE TRAINING LEFT VENTRICULAR REMODELING IN MALES AND FEMALES RATS
CARRANZA VB; PINILLA OA; ESCUDERO EM
Buenos Aires Argentina
Congreso; World Congress of Cardiology; 2008
Introduction: at baseline male and female hearts display several differences in coronary artery size, electrophysiological properties, patterns expression of certain genes and contractile properties. Differences in the remodelling responses can also be seen in rodents with pressure overload, volume overload and myocardial infarction. However the sex-dependent response of LV to exercise training has not been completely study up to now .The purpose of this study is to analyze by echocardiogram LV remodeling secondary to exercise in males and females rats. Material and methods: M-mode echocardiographic was performed under two-dimensional control in 19 Wistar, 4-month old rats. LV mass (LVM), LVM index (LVMI) as LVM / tibia length and relative wall thickness (RWT) as LV posterior wall thickness / diastolic diameter, was calculated with echocardiographic parameters. 11 rats, 7 males (ME) and 4 females (FE) were trained swimming 90 minutes a day, 5 days a week during 8 weeks. 8 rats, 5 males (MC) and 3 (FC) were controls. Systolic blood pressure (SBP) determined by the tail-cuff method and heart rate (HR) was obtained in each rat. All animals were sacrificed at the end of protocol to obtain LV weight and tibia length. Results: LVMI was higher in the exercise group (E) (MC: 193.2 ± 4.99 mg/cm; ME: 231.6 ± 13 mg/cm p<0.04 FC: 110.76 ± 1.34 mg/cm; FE: 120.92 ± 1.93 mg/cm p<0.01). ME had showed a higher proportional increment of LVMI than FE (ME: 53.16±8.85 % ; FE: 16.17±2.87 % ). ME developed a LV concentric remodeling (h/r MC: 0.44 ± 0.02; ME: 0.52 ± 0.02 p<0.03), not present in FE instead of the LV hypertrophy (h/r FC: 0.44 ± 0.01; FE: 0.45±0.02-ns). LV function, evaluated by endocardial and mid-ventricular shortening and myocardial performance index was similar in both groups. Conclusion: the exercise training by swimming produced an LV adaptative response both in males and females rats. The adaptative response was identified by the development of LV hypertrophy without changes in LV function. Remodeling in male rats was characterized by a proportional higher increase of LVM with concentric pattern. This evidence could be interpreted as a sex-dependence of the exercise training LV remodelling