Study of cardiovascular autonomic adaptations induced by pharmacological treatment in association with aerobic physical training in spontaneously hypertensive rats (SHR)

Abstract

Several factors can predispose an individual to systemic arterial hypertension. Some of these factors are related to the lifestyle, such as alcohol consumption and sodium/fat-rich diet, overweight, and mainly sedentarism, which increases the risk of developing the disease. Therefore, the aerobic physical training has beneficial effects on the cardiovascular system in both preventing and treating hypertension. However, little is known about such effects when different classes of anti-hypertensive drugs are associated. Thus, the objective of the present work is to study and compare the effects of anti-hypertensive drugs in association with aerobic physical training on the cardiac autonomic control in spontaneously hypertensive rats (SHR). The rats were distributed into two main groups: sedentary group (N = 72) and trained group (N = 72), with animals being submitted to daily 60-minute sessions of aerobic exercise (swimming) during 10 weeks. Each main group was further divided into 6 subgroups (N = 12), with animals being fed with water containing the following substances: placebo, enalapril (30 mg*kg1*d1), losartan (30 mg*kg1*d1), hydrochlorothiazide (10 mg*kg1*d1), propranolol (10 mg*kg1*d1), and amlodipine (10 mg*kg1*d1). Evaluation protocols include the following approaches: assessment of cardiac autonomic tonus by means of pharmacological double blockade with methylatropine and propranolol; baroreflex sensitivity; analysis of heart rate variability and systolic arterial pressure; and catecholamine plasma levels. (AU)