Pharmacological characterization of rat amylin receptors: implications for the identification of amylin receptor subtypes
Pharmacological characterization of rat amylin receptors: implications for the identification of amylin receptor subtypes
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DOI：
10.1111/j.1476-5381.2011.01717.x
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发表时间：
2012-05-01
影响因子：
7.3
通讯作者：
Hay, D. L.
中科院分区：
文献类型：
--
作者：
Bailey, R. J.;Walker, C. S.;Hay, D. L.
背景与目的胰淀素（Amylin，Amy）是一种重要的糖调节肽，AMY受体是糖尿病和肥胖的临床靶点。人（h）AMY受体亚型是降钙素（CT）受体与受体活性修饰蛋白（RAMP）的复合物;其啮齿动物对应物尚未表征。为了鉴定最具临床相关性的受体亚型，有必要阐明大鼠（r）AMY受体药理学。实验方法将受体瞬时转染到COS-7细胞中，并测量cAMP对不同激动剂（有或没有拮抗剂）的应答。进行竞争结合实验以确定rAmy亲和力。关键结果rCT是rCT（a）受体最有效的激动剂，而rAmy对rAMY 1（a）和rAMY 3（a）受体最有效。rAmy以高亲和力与这些受体结合。大鼠α-降钙素基因相关肽（CGRP）在两种AMY受体上与rAmy等效。大鼠肾上腺髓质素（AM）和rAM 2/intermedin激活所有三种受体，但在rAMY 3（a）最有效。AC 187、AC 413和sCT 8 -32是所有三种受体的有效拮抗剂。raCGRP 8 -37对rAMY受体的选择性高于rCT（a）受体。rAMY 8 -37是一种弱拮抗剂，但对rAMY 1（a）比rAMY 3（a）更有效。结论和意义AMY受体是由rCT（a）与rRAMP 1或3共表达产生的，分别形成rAMY 1（a）和rAMY 3（a）受体。CGRP对rAMY比对hAMY受体更有效。没有测试的拮抗剂能够区分rAMY受体亚型。这些数据强调了开发新的CT或AMY受体配体作为药理学工具或潜在的临床候选物的需要，并为开发新的CT或AMY受体配体提供了有用的资源。
BACKGROUND AND PURPOSE Amylin (Amy) is an important glucoregulatory peptide and AMY receptors are clinical targets for diabetes and obesity. Human (h) AMY receptor subtypes are complexes of the calcitonin (CT) receptor with receptor activity-modifying proteins (RAMPs); their rodent counterparts have not been characterized. To allow identification of the most clinically relevant receptor subtype, the elucidation of rat (r) AMY receptor pharmacology is necessary. EXPERIMENTAL APPROACH Receptors were transiently transfected into COS-7 cells and cAMP responses measured in response to different agonists, with or without antagonists. Competition binding experiments were performed to determine rAmy affinity. KEY RESULTS rCT was the most potent agonist of rCT(a) receptors, whereas rAmy was most potent at rAMY1(a) and rAMY3(a) receptors. rAmy bound to these receptors with high affinity. Rat a-calcitonin gene-related peptide (CGRP) was equipotent to rAmy at both AMY receptors. Rat adrenomedullin (AM) and rAM2/intermedin activated all three receptors but were most effective at rAMY3(a). AC187, AC413 and sCT8-32 were potent antagonists at all three receptors. raCGRP8-37 displayed selectivity for rAMY receptors over rCT(a) receptors. rAMY8-37 was a weak antagonist but was more effective at rAMY1(a) than rAMY3(a). CONCLUSIONS AND IMPLICATIONS AMY receptors were generated by co-expression of rCT(a) with rRAMP1 or 3, forming rAMY1(a) and rAMY3(a) receptors, respectively. CGRP was more potent at rAMY than at hAMY receptors. No antagonist tested was able to differentiate the rAMY receptor subtypes. The data emphasize the need for and provide a useful resource for developing new CT or AMY receptor ligands as pharmacological tools or potential clinical candidates.