METABOTROPIC GLUTAMATE-RECEPTOR AGONISTS STIMULATE POLYPHOSPHOINOSITIDE HYDROLYSIS IN PRIMARY CULTURES OF RAT HEPATOCYTES

The metabotropic glutamate (mGlu) receptor agonists, quisqualate and ( 1S,3R)-1-aminocyclopentane-1,3-dicarboxylic acid (ACPD), but not (RS)- 3,5-dihydroxyphenylglycine or (2S,3S,45)-alpha-(carboxycyclopropyl)gly cine, stimulated [H-3]inositolmonophosphate ([H-3]InsP) formation in p rimary cultures of rat hepatocytes. 1S,3R-ACPD-stimulated [H-3]InsP fo rmation was inhibited by alpha-methyl-4-carboxyphenylglycine, indicati ng that cultured hepatocytes express functional mGlu receptors coupled to polyphosphoinositide hydrolysis. The identity of these receptors i s not similar to that of any of the known mGlu receptor subtypes chara cterized in heterologous expression systems. (C) 1997 Elsevier Science B.V.