Avaliação da função vascular induzida pela exposição in vitro ao cádmio em aorta de ratas wistar

Abstract

Cadmium exposure has been linked to several cardiovascular diseases. Experimental studies, carried out in males, demonstrate that this metal induces important vascular dysfunction. In females, a recent study found that subchronic exposure to CdCl2 does not modify blood pressure and vascular reactivity to phenylephrine in isolated aorta. However, effects induced by in vitro exposure to Cd in females have not been described so far. Therefore, we aimed to investigate the in vitro effects of cadmium chloride (ClCd2, 5 µM) on vascular reactivity in isolated aorta of Wistar rats. The rats were anesthetized, euthanized and the thoracic aorta was removed to assess vascular reactivity. Control rings and rings previously incubated with 5μM of Cd were submitted to different experimental protocols. Our results demonstrate that in vitro exposure to ClCd2 at low concentrations was able to damage the vascular endothelium architecture and reduce the anticontractile modulation of perivascular adipose tissue (PVAT) on vascular reactivity to phenylephrine. In the absence of PVAT, although Cd did not modify the reactivity to phenylephrine, an increase in the production and basal release of O2 •- , a reduction in the participation of K+ channels, an increase in the participation of the Ang II pathway and an increase in the release of PGI2 and/or reduction of constricting prostanoids. Furthermore, it was possible to observe that in the presence of Cd, ERα receptors negatively modulate vascular reactivity to phenylephrine. Taken together, these results demonstrate that in vitro exposure to Cd promotes important vascular dysfunction in isolated aorta associated with changes in its architecture and endothelial vasoactive pathways, which could contribute to vasculopathies associated with exposure to this metal.