Abstract
We examined the effects of glutamate receptor agonists on cyclic AMP (cAMP) formation in cultured astrocytes. L-Glutamate reduced the cAMP formation induced by either isoproterenol (IC50 7 microM) or forskolin without affecting the basal level. Glutamate agonists reduced the cAMP formation in astrocytes with the following rank order of potency: L-glutamate > trans-(+/-)-1-aminocyclopentane-1,3-dicarboxylic acid (t-ACPD) = quisqualate. Pretreatment of astrocytes with pertussis toxin resulted in a partial reduction of the glutamate response and a complete attenuation of the t-ACPD response. These results suggest that astrocytes have another type of metabotropic glutamate receptor which inhibits adenylate cyclase through pertussis toxin-sensitive G-proteins.
Publication types
-
Research Support, Non-U.S. Gov't
MeSH terms
-
Adenylate Cyclase Toxin
-
Animals
-
Animals, Newborn
-
Astrocytes / metabolism*
-
Cells, Cultured
-
Colforsin / pharmacology
-
Cyclic AMP / biosynthesis*
-
Cycloleucine / analogs & derivatives
-
Cycloleucine / pharmacology
-
Excitatory Amino Acid Antagonists
-
Iodine Radioisotopes
-
Isoproterenol / pharmacology
-
Pertussis Toxin
-
Quisqualic Acid / pharmacology
-
Rats
-
Rats, Sprague-Dawley
-
Receptors, Glutamate / drug effects*
-
Virulence Factors, Bordetella / pharmacology
Substances
-
Adenylate Cyclase Toxin
-
Excitatory Amino Acid Antagonists
-
Iodine Radioisotopes
-
Receptors, Glutamate
-
Virulence Factors, Bordetella
-
Cycloleucine
-
1-amino-1,3-dicarboxycyclopentane
-
Colforsin
-
Quisqualic Acid
-
Cyclic AMP
-
Pertussis Toxin
-
Isoproterenol