title: Novel potent selective phenylglycine antagonists of metabotropic glutamate receptors.
abstract: The metabotropic glutamate (mGlu) receptor antagonist properties of novel phenylglycine analogues were investigated in adult rat cortical slices (mGlu receptors negatively coupled to adenylyl cyclase), neonatal rat cortical slices and in cultured rat cerebellar granule cells (mGlu receptors coupled to phosphoinositide hydrolysis). (RS)-alpha-methyl-4-phosphonophenylglycine (MPPG), (RS)-alpha-methyl-4-sulphonophenylglycine (MSPG), (RS)-alpha-methyl-4-tetrazolylphenylglycine (MTPG), (RS)-alpha-methyl-3-carboxymethyl-4-hydroxyphenylglycine (M3CM4HPG) and (RS)-alpha-methyl-4-hydroxy-3-phosphonomethylphenylglycine (M4H3PMPG) were demonstrated to have potent and selective effects against 10 microM L-2-amino-4-phosphonobutyrate (L-AP4)- and 0.3 microM (2S,1'S,2'S)-2-(2-carboxycyclopropyl)glycine (L-CCG-1)-mediated inhibition of forskolin-stimulated cAMP accumulation in the adult rat cortex. In contrast, these compounds demonstrated either weak or no antagonism at mGlu receptors coupled to phosphoinositide hydrolysis in either neonatal rat cortex or in cultured cerebellar granule cells. These compounds thus appear to be useful discriminatory pharmacological tools for mGlu receptors and form the basis for the further development of novel antagonists.
authors.affiliation: Department of Pharmacology, School of Medical Sciences, University of Bristol, UK.
authors.forename: J S
authors.initials: JS
authors.lastname: Bedingfield
authors.forename: D E
authors.initials: DE
authors.lastname: Jane
authors.forename: M C
authors.initials: MC
authors.lastname: Kemp
authors.forename: N J
authors.initials: NJ
authors.lastname: Toms
authors.forename: P J
authors.initials: PJ
authors.lastname: Roberts
mesh_terms: D000818:Animals; D002478:Cells, Cultured / Q000187:drug effects; D002531:Cerebellum / Q000187:drug effects*; D002540:Cerebral Cortex / Q000187:drug effects*; D003515:Cycloleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005998:Glycine / Q000031:analogs & derivatives*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000037:antagonists & inhibitors*
chemical_list: D018094:Receptors, Metabotropic Glutamate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D005998:Glycine