Methoxy-PEPy is a potent and highly selective mGlu5 receptor antagonist with IC50 of 1 nM.IC50 value: 1 nM [1]Target: mGlu5R inhibitorAdministration of [3H]methoxy-PEPy (50 microCi/kg i.v.) to mGlu5 receptor-deficient mice revealed binding at background levels in forebrain, whereas wild-type mice exhibited 14-fold higher binding in forebrain relative to cerebellum [2]. The calcium transients stimulated by these agonists were potently inhibited by reference allosteric mGlu5 antagonists - 2-methyl-6-(phenylethynyl)pyridine (MPEP), 3-[(2-methyl-1,3-thiazol-4-yl)ethynyl]pyridine (MTEP) and 3-methoxy-5-(pyridine-2-ylethynyl)pyridine (methoxy-PEPy) (IC(50) ranges: 0.8-66 nM) [3].
[1]. Cosford ND, et al. [3H]-methoxymethyl-MTEP and [3H]-methoxy-PEPy: potent and selective radioligands for the metabotropic glutamate subtype 5 (mGlu5) receptor. Bioorg Med Chem Lett. 2003 Feb 10;13(3):351-4. [2]. Anderson JJ, et al. In vivo receptor occupancy of mGlu5 receptor antagonists using the novel radioligand [3H]3-methoxy-5-(pyridin-2-ylethynyl)pyridine). Eur J Pharmacol. 2003 Jul 18;473(1):35-40. [3]. Salisbury BG, et al. Inducible expression and pharmacological characterization of the mouse metabotropic glutamate 5b receptor. Eur J Pharmacol. 2008 Jan 28;579(1-3):34-9.