The enhancement and the inhibition of noradrenaline-induced cyclic AMP accumulation in rat brain by stimulation of metabotropic glutamate receptors.
The actions of several metabotropic glutamate receptor agonists and antagonists on noradrenaline (NA)-stimulated [3H]-cyclic AMP accumulation were investigated in rat cerebral cortical slices. Quisqualate (QUIS), L-2-amino-3-phosphonopropionic acid (L-AP3) and glutamate (GLU) elicited concentration-dependent inhibition of (NA)-stimulated [3H]-cyclic AMP accumulation. In contrast (2S,3S,4S)-alpha-(Carboxy-cyclopropyl)glycine (L-CCGI), 1-Aminocyclo-pentane-1S,3R-dicarboxylate (1S,3R-ACPD), ibotenate (IBO) and (RS)-4-carboxy-3-hydroxy-phenylglycine (CHPG) elicited a concentration-dependent enhancement of NA-stimulated [3H]-cyclic AMP accumulation. A putative mGluR antagonist-L-AP3, inhibited the 1S,3R-ACPD-induced enhancement of the action of NA on [3H]-cyclic AMP accumulation in a biphasic manner with an IC50 of 4.5 microM for the high affinity site, which represented 65% of the total and an IC50 of 283 microM for the low affinity site.
Legutko
B
B
Institute of Pharmacology, Polish Academy of Sciences, Kraków, Poland.
Pałucha
A
A
Branski
P
P
Pilc
A
A
D000818:Animals; D001921:Brain / Q000378:metabolism*; D000242:Cyclic AMP / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D018094:Receptors, Metabotropic Glutamate / Q000819:agonists / Q000037:antagonists & inhibitors / Q000502:physiology*; D013268:Stimulation, Chemical
D018094:Receptors, Metabotropic Glutamate; D000242:Cyclic AMP; D009638:Norepinephrine