Control of arteriovenous anastomoses in rabbit ear model of digital perfusion.
Control of arteriovenous anastomoses in rabbit ear model of digital perfusion.
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数字灌注兔耳模型动静脉吻合的控制。
DOI：
10.1152/ajpheart.1996.271.5.h2007
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发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Smith,TL
中科院分区：
文献类型：
--
作者：
Pollock,DC;Li,Z;Koman,LA;Gordon,ES;Smith,TL
手脚皮肤微循环的动静脉吻合（AVA）是体温调节血流的基本决定因素，可能与寒冷不耐受有关。这些直接微血管研究是对参与麻醉雄性新西兰白兔耳内 AVA 控制的肾上腺素能受体亚型的初步表征。用去氧肾上腺素刺激肾上腺素 α1 会产生 AVA 收缩，而特拉唑嗪（α1 拮抗剂）则产生扩张并减弱对去氧肾上腺素的反应。 UK-14304 的肾上腺素 α 2 刺激产生 AVA 收缩，而阿替美唑（α 2 拮抗剂）产生扩张并减弱对 UK-14304 的反应。当研究等摩尔浓度的拮抗剂时，α2-阻断产生的AVA扩张大于α1-阻断产生的AVA扩张。去甲肾上腺素（α1-和α2-激动剂混合）也会产生血管收缩作用，哌唑嗪（α1-拮抗剂）和阿替美唑均可减弱血管收缩作用。总之，1) AVA 包含 α 1- 和 α 2- 受体的异质混合物，2) α 2- 受体对 AVA 整体音调的影响可能比 α 1- 受体更大。
The arteriovenous anastomoses (AVA) of the cutaneous microcirculation of the hands and feet are fundamental determinants of thermoregulatory blood flow and may be involved in cold intolerance. These direct microvascular studies are an initial characterization of adrenergic receptor subtypes participating in control of AVA in the ears of anesthetized male New Zealand White rabbits. Adrenergic alpha 1-stimulation with phenylephrine produced AVA constriction, whereas terazosin (an alpha 1-antagonist) produced dilation and attenuated the responses to phenylephrine. Adrenergic alpha 2-stimulation with UK-14304 produced constriction of the AVA, whereas atipamezole (an alpha 2-antagonist) produced dilation and attenuated the responses to UK-14304. When equimolar concentrations of antagonists were studied, the AVA dilation produced by alpha 2-blockade was greater than that produced by alpha 1-blockade. Norepinephrine (a mixed alpha 1- and alpha 2-agonist) also produced vasoconstriction, which was attenuated by both prazosin (an alpha 1-antagonist) and atipamezole. In summary, 1) AVA contain a heterogeneous mixture of both alpha 1- and alpha 2-receptors, and 2) alpha 2-receptors may have a greater influence than alpha 1-receptors on overall tone in AVA.