P44 Carboxymethyl-glucan extracted from Saccharomyces cerevisiae induces vasodilation mediated by the NOS/NO/SCG pathway and negative inotropic effects in rats

Abstract

Carboxymethyl-glucans are derived solubles of β-D-glucans, known to be biologically active molecules presenting immunomodulation, antioxidant and platelet anti-aggregation activity. This study evaluated the effect of carboxymethyl-glucan from Saccharomyces cerevisiae (CM-G) on vascular reactivity, investigating the mechanisms of action involved; atrial contractility and transient calcium in ventricular cardiomyocytes. Experiments were designed with healthy animals which were divided into two groups: one treated orally with CM-G at a dose of 50 mg/kg, daily, during 21 days; and another with saline solution. Afterward, experiments were carried out using an animal model of acute myocardial infarction induced by isoproterenol, in which on days 20 and 21 of the experiment were administered 85 mg/kg/day of isoproterenol by subcutaneous injection. On the 22th day, at 48 h after administration of the first isoproterenol dose, experimental tests were conducted. CM-G provoked concentration dependent vasorelaxant effect in functional endothelium vessels. This effect was significantly reduced in pre-incubated rings with L-NAME, ODQ or carboxy-PTIO. Treatment with CM-G increased the effectiveness of acetylcholine-induced relaxation. The results show that CM-G positively modulated the vascular endothelium, leading to relaxation in the rat aorta via NOS/NO/sCGs, in addition to acting on the myocardium, inducing a negative inotropic effect.