vasoconstrictor (vā´zōkənstrik´tur) , n (vasopressor), an agent that causes a rise in blood pressure by constricting the blood vessels. In local areas, it causes constriction of the arterioles and capillaries. Vasoconstrictor agents. 2  vasoconstrictor center. 3  vasoconstrictor center. 4  vasoconstrictor center. 5  vasoconstrictor center. 6  vasoconstrictor fibers. 7  vasoconstrictor fibers. 8  vasoconstrictor fibers. 9  vasoconstrictor nerve. 10  vasoconstrictor nerve.