Study of the association of aerobic exercise with different pharmacological therapies on cardiac autonomic adaptations 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 of their effects in the short and long term when combined with different classes of antihypertensive drugs. 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). Therefore, 18 weeks old SHR will be divided into two major groups: group of rats treated for 12 weeks (N = 96) and group of rats treated for 50 weeks (N = 96). Each large group will be divided into two smaller groups; sedentary group (N = 48) and trained group (N = 48) through daily sessions of exercise (swimming) for 10 weeks. Finally, each trained or untrained group will be subdivided into 06 subgroups (n = 16) are treated in the drinking water for 12 or 50 weeks, with the following substances; placebo, enalapril (10 mg*kg1*d1), losartan (05 mg*kg1*d1), hydrochlorothiazide (10 mg*kg1*d1), propranolol (05 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)