包装 | 价格(元) |
10mg | 电议 |
50mg | 电议 |
100mg | 电议 |
Cell experiment: | HEK293 cells stably transfected with CLR/RAMP1 are plated in complete growth medium at 85,000 cells/well in 96-well poly-D-lysine-coated plates and cultured for 19 h before assay. Cells are washed with PBS and then incubated with inhibitor in the presence or absence of 50% human serum for 30 min at 37℃ and 95% humidity in Cellgro Complete Serum-Free/Low-Protein medium with L-glutamine and 1 g/L bovine serum albumin. Isobutylmethylxanthine is added to the cells at a concentration of 300 μM and incubated for 30 min at 37℃. Human α-CGRP is added to the cells at a concentration of 0.3 nM and allowed to incubate at 37℃ for 5 min. After α-CGRP stimulation, the cells are washed with PBS and processed for cAMP determination using the two-stage assay procedure according to the manufacturer's recommended protocol. Dose-response curves are plotted, and IC50 values are determined. |
Animal experiment: | Monkeys: Rhesus monkeys (male and female) weighing between 4 and 10 kg are anesthetized initially with ketamine (0.1 mL/kg i.m.) and then placed in the supine position on a temperature-controlled water circulating blanket and intubated with a 3-mm tracheal tube connected to 1-liter oxygen/1 to 2% isoflurane gas anesthesia. The right saphenous vein is cannulated for intravenous drug delivery, and blood samples are obtained from the left saphenous artery. Four rubber O-rings (8 mm inner diameter) are placed on the ventral side of the forearm without directly being positioned over a visible vessel. |
产品描述 | MK-0974 (Telcagepant) is a highly potent, selective, and orally bioavailable antagonist of CGRP receptor with IC50 value of 0.77 nM [1]. Calcitonin gene-related peptide (CGRP) receptor is a heteromeric transmembrane receptor composed of a G protein-coupled receptor which is called calcitonin receptor-like receptor (CALCRL) and a receptor activity modifying protein 1 (RAMP1). CGRP receptor is functional for mediating the activity of CGRP, which is widely distributed in human peripheral and central neuron system. The CGRP/CGRP receptor signaling pathway modulate a variety of physiological functions of respiratory, immune and cardiovascular system, and play a key role in the pathophysiology of migraine headache. When binding study was carried out, it was found MK-0974 had high affinity for CGRP receptor but had no affinity for related human adrenomedullin receptors, which suggested the high specificity of MK-0974 [1]. In human HEK293 cells expressing CGRP receptor, treatment of MK-0974 resulted in potent blockage of α-CGRP-stimulated cAMP producation, which indicated a significant inhibition of CGRP receptor activity. However, addition of 50% human serum reduced the inhibition potency of MK-0974 by 5-fold [1]. 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 [2]. In rhesus model, capsaicin-induced release of endogenous CGRP resulted in dermal vasodilation. Following treatment of MK-0974 produced a dose-dependent inhibition of dermal vasodilation, with plasma concentrations of 127 and 994 nM required to block 50 and 90% of the blood flow increase, respectively. The suppression of CGRP function indicated the inhibition of CGRP receptor by MK-0974 [1]. In monkey model, MK-0974 showed moderate clearance (14-20 ml min-1 kg-1), while oral bioavailability was 6%. The pharmacokinetics of MK-0974 remained linear across 0.5-10 mg kg-1 intravenous dose in monkeys, but the oral area under the plasma concentration-time curve (AUC) increase (5-30 mg kg-1) was 15-fold over dose-proportional [3]. References: |