agent that narrows blood vessels: an agent that narrows the blood vessels, which in turn increases resistance to blood flow and raises blood pressure, e.g. a nerve or hormone. Vasoconstrictors such as the hormone epinephrine and various drugs are used medically to maintain or raise blood pressure in circulatory disorders or during surgery, or to counteract shock.
adjective
Definition:
narrowing blood vessels: causing narrowing of the blood vessels
