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Medical Term:


Pronunciation: nor'ep-i-nef'rin

Definition: A catecholamine hormone the natural form of which is d, although the l form has some activity; the base is considered to be the postganglionic adrenergic mediator, acting on a and ß receptors; it is stored in chromaffin granules in the adrenal medulla in much smaller amounts than epinephrine and secreted in response to hypotension and physical stress; in contrast to epinephrine it has little effect on bronchial smooth muscle, metabolic processes, and cardiac output, but has strong vasoconstrictive effects and is used pharmacologically as a vasopressor, primarily as the bitartrate salt.

Synonym(s): levarterenol, noradrenaline

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