histamine(redirected from H substance (inflammation))
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A physiologically active amine, C5H9N3, found in plant and animal tissue and released from mast cells as part of an allergic reaction in humans. It stimulates gastric secretion and causes dilation of capillaries, constriction of bronchial smooth muscle, and decreased blood pressure.
his′ta·min′ic (-mĭn′ĭk) adj.
(Biochemistry) an amine formed from histidine and released by the body tissues in allergic reactions, causing irritation. It also stimulates gastric secretions, dilates blood vessels, and contracts smooth muscle. Formula: C5H9N3. See also antihistamine
[C20: from hist(idine) + -amine]
his•ta•mine(ˈhɪs təˌmin, -mɪn)
a histidine-derived amine compound that is released mainly by damaged mast cells in allergic reactions, causing dilation and permeability of blood vessels and lowering blood pressure.
his`ta•min′ic (-ˈmɪn ɪk) adj.
An organic compound found widely in animals and plants. In humans and other mammals, histamine is released as part of the body's immune response, causing a variety of changes in the body including enlargement of the blood vessels, tightening of the airways, and faster beating of the heart. The itchiness and sneezing typical of an allergic reaction are caused by the release of histamine.
A hormone in almost all body tissues, released by antigen—antibody reactions. Its effects include making blood vessels expand and leak.
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|Noun||1.||histamine - amine formed from histidine that stimulates gastric secretions and dilates blood vessels; released by the human immune system during allergic reactions|