AGONISTS FOR METABOTROPIC GLUTAMATE RECEPTORS IN THE RAT DELAY RECOVERY FROM HALOTHANE ANESTHESIA

Intraventricular injection of (2S,1'R,2'R,3'R)-2-(2,3-dicarboxycyclopr (DCG-IV), a potent agonist for metabotropic glutamate receptors, to r ats retarded dose-dependently the recovery from halothane anesthesia a t a dose range from 30 to 300 pmol/rat. At a dose of 300 pmol/rat, rec overy was prolonged up to about 630% of the control. (2S,1'S,2'S)-2-(c arboxycyclopropyl)glycine (L-CCG-I) and (1S,3R)-1-aminocyclopentane-1, 3-dicarbox acid ((1S,3R)-ACPD) also delayed recovery, but doses much h igher than those of DCG-IV were required (about 300 and 1000 times, re spectively). These results suggest that some agonists for a certain ki nd of metabotropic glutamate receptors have a central depressant actio n in the rat.