Recent work from our laboratory indicates that Epithelial Na⁺ Channel (ENaC) function plays an important role in modulating myogenic vascular reactivity. Increases in dietary sodium are known to affect vascular reactivity. While previous studies have demonstrated that dietary salt intake regulates ENaC expression and activity in epithelial tissue, the importance of dietary salt on ENaC expression in vascular smooth muscle cells (VSMC) and its role in myogenic constriction is unknown. Therefore, the goal of the present study was to determine whether dietary salt modulates ENaC expression and function in myogenic vasoconstriction. To accomplish this goal, we examined ENaC expression in freshly dispersed VSMC, and pressure-induced vasoconstrictor responses in isolated mesenteric resistance arteries from normotensive Sprague-Dawley rats fed a normal salt (NS, 0.4% NaCl) or HS diet (8% NaCl, 2 wks). VSMCs from mesenteric arteries of NS fed animals express , and ENaC. HS diet reduced whole cell and ENaC and induced a pronounced translocation of ENaC from intracellular regions towards the VSMC membrane (~336 nm). Associated with this change in expression, was a change in the importance of ENaC in pressure-induced constriction. Pressure-induced constriction in NS fed animals was insensitive to ENaC inhibition with 1 microM benzamil, suggesting ENaC proteins do not contribute to myogenic constriction in mesenteric arteries under normal salt intake. In contrast, ENaC inhibition blocked pressure-induced constriction in HS fed animals. These data suggest that dietary sodium regulates ENaC expression and the quantitative importance of the vascular ENaC signaling pathway contributing to myogenic constriction.