Functional coupling between metabotropic glutamate receptors and G proteins in rat brain membranes.
Functional activation of GTP-binding (G) proteins coupled with metabotropic glutamate receptors was evaluated in rat brain membranes. L-Glutamate stimulated the high-affinity GTPase activity in cerebral cortical, hippocampal, and striatal membranes with a mean concentration eliciting a half-maximal response (EC50) of 4.8, 1.6, and 4.9 microM, respectively. The enzyme activity in cerebral cortical membranes was also stimulated by (2S, 1'S,2'S)-2-(carboxycyclopropyl)glycine (L-CCG-I) with a mean EC50 of 0.90 microM, but not by L-2-amino-4-phosphonobutyrate (L-AP4) up to 10 microM. This method opens up a strategy for investigation of functional coupling between Group II metabotropic glutamate receptors and G proteins in native brain membranes.
Odagaki
Y
Y
Department of Psychiatry, Hokkaido University School of Medicine, Sapporo, Japan.
Nishi
N
N
Koyama
T
T
D000600:Amino Acids, Dicarboxylic / Q000494:pharmacology; D000613:Aminobutyrates / Q000494:pharmacology; D000818:Animals; D002462:Cell Membrane / Q000201:enzymology / Q000378:metabolism; D002540:Cerebral Cortex / Q000201:enzymology / Q000378:metabolism*; D018690:Excitatory Amino Acid Agonists / Q000494:pharmacology; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism; D008297:Male; D011485:Protein Binding / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D018094:Receptors, Metabotropic Glutamate / Q000378:metabolism*; D013268:Stimulation, Chemical
D000600:Amino Acids, Dicarboxylic; D000613:Aminobutyrates; D018690:Excitatory Amino Acid Agonists; D018094:Receptors, Metabotropic Glutamate; C035261:(alpha-carboxycyclopropyl)glycine; D020558:GTP Phosphohydrolases; D019204:GTP-Binding Proteins; C012729:2-amino-4-phosphonobutyric acid