The vasodilator mechanisms of sodium metabisulfite on precontracted isolated aortic rings in rats: Signal transduction pathways and ion channels

► SMB could relax isolated rat aortic rings in a concentration-dependent manner. ► Endothelium-dependent relaxation caused by SMB at low concentrations was about 20%. ► Vasorelaxation at low concentrations was involved in cGMP pathway, BKCa channel. ► Endothelium-independent relaxation by SMB at high concentrations was more than 90%. ► Vasorelaxation at high concentrations was mediated by KATP and L-type Ca2+ channel.