n :  any of a group of receptors postulated to exist on cell surfaces of some effector organs and tissues innervated by the sympathetic nervous system to explain the specificity of certain adrenergic agents in activating or blocking only some sympathetic activities (as vasodilation, increase in muscular contraction and beat of the heart, and relaxation of smooth muscle in the bronchi and intestine) - called also beta-adrenergic receptor , beta-adrenoceptor  - compare ALPHA-RECEPTOR  .
 
 chiefly Brit   
 
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