Vasoconstrictors and nitrovasodilators reciprocally regulate the Na+-K+-2Cl- cotransporter in rat aorta

The activity of Na+-K+-2Cl- cotransporter NKCC1 in vascular smooth muscle was measured as the bumetanide-sensitive efflux of 86Rb+ from intact smooth muscle of the rat aorta. Results showed that the Na+-K+-2Cl- cotransporter in vascular smooth muscle is reciprocally controlled by vasoconstrictors and nitrovasodilators and contributes to smooth muscle contraction, indicating that changes in NKCC1 could affect vascular smooth muscle tone in vivo.