Nicotinic versus muscarinic binding sites in cat and rabbit carotid bodies.
Nicotinic versus muscarinic binding sites in cat and rabbit carotid bodies.
复制标题
猫和兔颈动脉体中的烟碱与毒蕈碱结合位点。
DOI：
10.1159/000109319
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发表时间：
1992
期刊：
影响因子：
--
通讯作者：
Fidone,S
中科院分区：
文献类型：
--
作者：
Hirano,T;Dinger,B;Yoshizaki,K;Gonzalez,C;Fidone,S
有研究表明，乙酰胆碱(ACh)可能在颈动脉小体化学感受中起重要作用。然而，对于ACh在这个器官中的作用一直缺乏统一的解释，部分原因是这种药物对不同动物物种的颈动脉窦神经放电具有相反的药理作用，最著名的是猫，在猫身上，ACh是兴奋的，而在兔子身上，ACh是抑制的。在本研究中，我们利用受体结合技术来比较这两个物种颈动脉小体中的烟碱和毒扁豆碱受体种群。我们对烟碱配体125I-Α-银环蛇毒素和毒扁豆碱配体~3H-奎宁基苯甲酸酯的研究结果表明，在猫体内，烟碱受体以2：1的比例占优势，而在兔体内，12：1的比例有利于毒碱受体。我们的数据表明，这两种动物颈动脉小体中M受体和烟碱受体的相对数量决定了外源性ACh在这个化学感受器中的兴奋或抑制作用。
It has been suggested that acetylcholine (ACh) might play an important role in carotid body chemoreception. However, a unified explanation of the actions of ACh in this organ has been lacking, due in part to the opposite pharmacological effects of this agent on carotid sinus nerve discharge in different animal species, most notably the cat, where ACh is excitatory, versus the rabbit, where it is inhibitory. In the present study, we utilized receptor binding techniques to compare the nicotinic and muscarinic receptor populations in the carotid bodies of these two species. Our results with the nicotinic ligand125I-Α-bungarotoxin and the muscarinic ligand3H-quinuclidinyl benzilate suggest that nicotinic receptors predominate in the cat by a ratio of 2:1, while in the rabbit, a 12:1 ratio favors muscarinic receptors. Our data suggest that the relative numbers of muscarinic and nicotinic receptors in the carotid bodies of these two species determine the excitatory or inhibitory actions of exogenously administered ACh in this chemoreceptor organ.