Definitions for "Histamine"
Keywords:  basophil, mast, amine, itch, allergic
an amino acid derivative derived from mast cells or basophils that causes rapid contraction of smooth muscles and increased vascular permeability resulting in bronchospasm, vascular congestion and edema.
A substance produced by the body in reaction to exposure to allergens; it causes eyes to tear and itch, nasal passages to swell, the nose to run, and sneezing to occur.
A compound formed by decarboxylation of histidine. Potent pharmacological agent acting through receptors in smooth muscle and in secretory systems. Stored in mast cells and released by antigen, as in the process of allergic reaction. It causes smooth muscle contraction of bronchioles and small blood vessels and increases the permeability of capilaries as well as secretion by nasal and bronchial mucus glands.