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,4S)-α-(carboxycyclopropyl)glycine stimulated [3H]inositolmonophosphate ([3H]InsP) formation in primary cultures of rat hepatocytes. 1S,3R-ACPD-stimulated [3H]InsP formation was inhibited by α-methyl-4-carboxyphenylglycine, indicating that cultured hepatocytes express functional mGlu receptors coupled to polyphosphoinositide hydrolysis. The identity of these receptors is not similar to that of any of the known mGlu receptor subtypes characterized in heterologous expression systems.