ALPHA-ADRENORECEPTOR SUBTYPES IN BLOOD-VESSELS - PHYSIOLOGY AND PHARMACOLOGY
ALPHA-ADRENORECEPTOR SUBTYPES IN BLOOD-VESSELS - PHYSIOLOGY AND PHARMACOLOGY
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DOI：
10.1097/00005344-198406004-00001
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发表时间：
1984-01-01
影响因子：
3
通讯作者：
HICKS, PE
中科院分区：
文献类型：
--
作者：
LANGER, SZ;HICKS, PE
神经传递领域的一个重要进展是发现了去甲肾上腺素能神经末梢上的突触前释放调节α-肾上腺素受体。突触前调节去甲肾上腺素释放的概念与α-肾上腺素受体两种亚型的药理学证据平行发展，这两种亚型由激动剂和拮抗剂的亲和力和相对效力顺序的不同特征所定义。甲氧胺和环唑啉优先刺激α 1-肾上腺素受体，哌唑嗪或柯楠碱选择性阻断α 1-肾上腺素受体。α 2-肾上腺素受体优先被激动剂如可乐定、TL-99、GHT-933和UK-14，304刺激，并且由这些激动剂介导的反应被α 2-肾上腺素受体拮抗剂咪唑克生选择性地阻断。在血管中，α 1-和α 2-肾上腺素受体亚型都存在于突触后，在那里它们介导血管收缩，尽管α 1-肾上腺素受体是血管平滑肌中的主要受体。在突触前去甲肾上腺素能神经末梢上，抑制性α 2-肾上腺素受体的刺激减少了递质的去极化诱发释放。在大多数血管床中，α 1肾上腺素受体也是优先受神经支配的亚型。在自发性高血压大鼠，平滑肌α 2-肾上腺素受体介导的血管收缩反应，外源性去甲肾上腺素和交感神经刺激在更大程度上比相应的血压正常的Wystar-Kyoto大鼠，这可能指向这些α 2-肾上腺素受体在高血压的病理生理作用。
A significant advance in the field of neurotransmission was made with the discovery of presynaptic release-modulating alpha-adrenoreceptors on noradrenergic nerve terminals. The concept of presynaptic modulation of noradrenaline release developed in parallel with the pharmacological evidence for two subtypes of alpha-adrenoreceptors as defined by a different profile of affinity and relative order of potencies for agonists and for antagonists. The alpha 1-adrenoreceptor is stimulated preferentially by methoxamine and cirazoline and blocked selectively by prazosin or corynanthine. The alpha 2-adrenoreceptor is stimulated preferentially by agonists such as clonidine, TL-99, GHT-933, and UK-14,304, and the responses mediated by these agonists are selectively blocked by the alpha 2-adrenoreceptor antagonist idazoxan. In blood vessels, both the alpha 1-and the alpha 2-adrenoreceptor subtypes are present postsynaptically, where they mediate vasoconstriction, although the alpha 1-adrenoreceptor is the predominant receptor in vascular smooth muscle. Presynaptically on noradrenergic nerve terminals, the stimulation of inhibitory alpha 2-adrenoreceptors reduces the depolarization-evoked release of the transmitter. In most vascular beds, the alpha 1-adrenoreceptor is also the preferentially innervated subtype. In spontaneously hypertensive rats, smooth-muscle alpha 2-adrenoreceptors mediate vasoconstrictor responses to exogenous noradrenaline and to sympathetic nerve stimulation to a greater extent than in the corresponding normotensive Wystar-Kyoto rats, which may point to a pathophysiological role of these alpha 2-adrenoreceptors in hypertension.