Reversible and non-competitive antagonist profile of CPCCOEt at the human type 1 α metabotropic glutamate receptor

Abstract

In transfected CHO cells expressing the human metabotropic glutamate receptor mGlu1 α, 7-(hydroxyimino)cyclopropan-[b]chromen-1a-carboxylic acid ethylester (CPCCOEt) was found to antagonize l-quisqualate-induced phosphoinositide hydrolysis in a non-competitive and reversible manner (apparent p K i value, 4.76±0.18; n=3). This suggests that CPCCOEt antagonizes type 1 α metabotropic glutamate receptor activation by interacting with a site distinct from the agonist binding site.