| adrenoreceptors | Reactive components of effector tissues, most of which are innervated by adrenergic postganglionic fibres of the sympathetic nervous system. Such receptor's can be activated by norepinephrine and/or epinephrine and by various adrenergic drugs; receptor activation results in a change in effector tissue function, such as contraction of arteriolar muscles or relaxation of bronchial muscles; adrenergic receptor's are divided into alpha-receptor's and beta-receptor's, on the basis of their response to various adrenergic activating and blocking agents. Synonym: adrenoceptor, adrenoreceptors. (05 Mar 2000) |
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| beta-adrenoreceptor antagonist | A class of drugs that compete with beta-adrenergic agonists for available receptor sites; some compete for both b1 and b2 receptors (e.g., propranolol) while others are primarily either b1 (e.g., metoprolol) or b2 blockers; used in the treatment of a variety of cardiovascular diseases where beta-adrenergic blockade is desirable. Synonym: beta-adrenergic receptor blocking agent, beta-adrenoreceptor antagonist, beta-blocker. (05 Mar 2000) |
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