Study of hemodynamic and morphometric cardiovascular adaptations promoted by different pharmacological treatments associated with aerobic physical training in hypertensive rats

Abstract

Hypertension is characterized by several cardiovascular disorders hemodynamic, morphometric and autonomic. Considering that in most cases this disease can be idiopathic and multicausal, some modifiable risk factors related to lifestyles, such as excessive alcohol intake, hyperlipidemic and hyper-sodium-chloride diet, increase in body fat percentage, and sedentary lifestyle, can significantly worsen the disease and lead to heart failure. In relation to treatment, the prescription of different types of drugs associated with changes in lifestyle, primarily through the practice of regular physical activity, can help control the disease in most cases. However, although beneficial in the prevention and treatment of hypertension, little is known of its hemodynamic, autonomic and heart tissue effects when combined with different types of antihypertensive drugs. It is not clear whether there are differences due to pharmacological treatments associated with physical exercises. Therefore, the present study aims to investigate the effects derived from the association between different antihypertensive pharmacological treatments and aerobic exercises on hemodynamic and cardiac morphometry in Spontaneously Hypertensive Rats (SHRs). SHRs will be divided into two large groups: Sedentary group (N = 48) and Trained group (N = 48) through 60-minute sessions of daily aerobic exercise (swimming) during 10 weeks. Each group will be subdivided into 6 smaller groups (N=08) and their drinking water will be supplemented during to 10 weeks with placebo, enalapril (30mg·kg1·d1), losartan (30mg·kg1·d1), hydrochlorothiazide (10mg·kg1·d1), propranolol (10mg·kg1·d1) and amlodipine (10mg·kg1·d1). Evaluation procedures will involve the following approaches: study of the evolution of blood pressure by telemetry; study of left ventricular systolic function; functional evaluation of cardiac contractility; quantification of the expression of cardiac beta-adrenergic receptors; dosage of serum catecholamines; and cardiac morphometric analysis.