Avaliação dos efeitos cardiovasculares e renais do extrato etanólico de Croton urucurana em ratos espontaneamente hipertensos

Abstract

Systemic arterial hypertension is an asymptomatic, multifactorial disease that affects more than 30% of the adult population worldwide. It has high morbidity and mortality rates and may be related to cerebrovascular and cardiovascular diseases. There is no cure for hypertension - therefore, its treatment is prolonged and wide, being divided into drug therapy and non-drug therapy, defined according to the needs of each patient. When prescribed, drugs act so that the body maintains or returns to a state of homeostasis and, consequently, regulates blood pressure parameters so they remain within normal values. However, there is a risk of drug interactions and possible drug resistance when in prolonged treatments, hence justifying the need to develop alternative methods. Thus, this study aims to investigate the cardiovascular and renal effects of compounds derived from Croton urucurana, a popular plant with anti-hypertensive potential, through its ethanolic extract (ESCU) administered in prolonged treatment (28 days) to spontaneously hypertensive rats (SHR). After evaluating biochemical, histopathological, toxicological parameters and also the mechanisms involved in the antihypertensive effect, it was concluded that, contrary to the initial hypothesis, ESCU is dose-dependent and does not act as a diuretic in the organism, but via the nitric oxide (NO) pathway through vasodilation – data corroborated by the inhibition of the extract in mesenteric beds a) without endothelium and; b) with endothelium treated with NO pathway inhibitor (LNAME). Furthermore, it is affirmed that ESCU action can be mediated by free Ca2+ activated small conductance K+ channels, since ESCU was inhibited in tests with mesenteric bed treated with specific and non-specific K+ blockers.