کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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2534506 | 1559093 | 2009 | 5 صفحه PDF | دانلود رایگان |
Calcitonin gene-related peptide (CGRP) is a neuropeptide that plays a key role in the pathophysiology of migraine headache. MK-0974 (telcagepant) is a potent and selective antagonist of the human and rhesus CGRP receptors and is currently in Phase III clinical studies for the acute treatment of migraine. The pharmacology of MK-0974 has been studied extensively, but there has not been a thorough characterization of its binding properties. Here, we characterize the binding of a tritiated analog of MK-0974 on human neuroblastoma (SK-N-MC) membranes and rhesus cerebellum. [3H]MK-0974 displayed reversible and saturable binding to both SK-N-MC membranes and rhesus cerebellum with a KD of 1.9 nM and 1.3 nM, respectively. Agonists and antagonists of the CGRP receptor displaced [3H]MK-0974 in a concentration-dependent manner in competition binding experiments. Both CGRP and adrenomedullin demonstrated biphasic competition while MK-0974 and the peptide antagonist CGRP(8-37) displaced [3H]MK-0974 in a monophasic fashion. In competitive binding studies with [3H]MK-0974 and CGRP, the fraction of high-affinity binding was reduced significantly by incubating the membranes with GTPγS. In kinetic binding experiments, the off-rate of [3H]MK-0974 was determined to be 0.51 min− 1 with a half-life of 1.3 min. In conclusion, the radioligand [3H]MK-0974 has proven to be a useful tool for studying the binding characteristics of MK-0974 and has broadened our understanding of this promising molecule.
Journal: European Journal of Pharmacology - Volume 602, Issues 2–3, 14 January 2009, Pages 250–254