Left ventricular performance and molecular myocardial signaling in rats after aerobic training on running and swimming

Abstract

The exercise training induces structural, functional and molecular changes in heart. For this adaptation, known as physiological cardiac hypertrophy, specific adaptive response to training type is an interesting issue. An increased thickness left ventricular (LV) wall as well as reduced LV cavity it has been shown to occur after anaerobic training, which is known as concentric LV hypertrophy. Aerobic training induce eccentric cavity remodeling, which is shown to be expressed as an increase in cavity radius and maintenance or minor change of wall thickness. Overall, this information led to assume that the cardiac remodeling induced by exercise is a clear issue. However, there are evidences that different types of aerobic training can also trigger a distinct cardiac remodeling. This issue is addressed in a research project supported by FAPESP (2013/20011-7), which will provide the following information: [1] LV hypertrophy is similar in rats submitted to swimming and running training; [2] LV function and myocardial in vitro performance are enhanced in both training method. In this new proposal, aim is to assess whether swimming and running induce similar molecular changes, which are well known to participate in the exercise-induced myocardial remodeling. Indeed, we will evaluate the adaptative myocardial response for phosphoinositide 3-kinase (PI3K±)/Akt1 to exercise training. In addition, miR-1 and miR-124 microRNA expression will also be evaluated in myocardial. This evaluation shows be carried out on light two factors: [1] hypertrophic heart is associated with reduced miR-1 and miR-124 expression after aerobic training; [2] an inverse relationship between miR-1/miR-124 expression and myocardial hypertrophy occurs in line with changes in PI3K±/Akt.