a substance, such as histamine or serotonin, that contains amino groups and is pharmacologically characterized by its action on the blood vessels (altering vascular caliber or permeability).
va·so·ac·tive a·mine
(vā'sō-ak'tiv ă-mēn') A substance, such as histamine or serotonin, which contains amino groups and is pharmacologically characterized by its action on the blood vessels (altering vascular caliber or permeability).