RT Journal Article
SR Electronic
T1 Anxiolytic-Like Effects of the Prototypical Metabotropic Glutamate Receptor 5 Antagonist 2-Methyl-6-(phenylethynyl)pyridine in Rodents
JF Journal of Pharmacology and Experimental Therapeutics
JO J Pharmacol Exp Ther
FD American Society for Pharmacology and Experimental Therapeutics
SP 1267
OP 1275
VO 295
IS 3
A1 Will P. J. M. Spooren
A1 Annick Vassout
A1 Hans C. Neijt
A1 Rainer Kuhn
A1 Fabrizio Gasparini
A1 Silvain Roux
A1 Roger D. Porsolt
A1 Conrad Gentsch
YR 2000
UL http://jpet.aspetjournals.org/content/295/3/1267.abstract
AB Recently, selective and systemically active antagonists for the metabotropic glutamate 5 receptor (mGlu5) were discovered, and the most potent derivative was found to be MPEP (2-methyl-6-(phenylethynyl)pyridine). Given the high expression of mGlu5 receptors in limbic forebrain regions, it was decided to evaluate the anxiolytic potential of MPEP. After an acute oral administration, MPEP attenuated the anxiety-dependent variable in a variety of well established anxiety test paradigms. In rats, MPEP (10, 30, and 100 mg/kg) increased punished responses in the Geller-Seifter test, but none of these effects reached statistical significance. MPEP significantly increased the ratio (open/total arm entries; 0.1, 1, and 10 mg/kg), the number of open arm entries (0.1, 1, and 10 mg/kg), as well as time spent on open arm (0.1 and 1 mg/kg) in the elevated plus maze test. Furthermore, MPEP (0.3 and 1 mg/kg) significantly increased the time spent in social contact in the social exploration test. In mice, MPEP attenuated stress-induced hyperthermia (15 and 30 mg/kg) and decreased the number of buried marbles in the marble burying test (7.5 and 30 mg/kg). Finally, MPEP (0.01, 0.1, 1, 10, and 100 mg/kg) was tested on spontaneous locomotor activity in mice, and only a dose of 100 mg/kg significantly reduced vertical activity; no effect was seen on horizontal activity. MPEP (7.5, 15, and 30 mg/kg) was ineffective ond-amphetamine-induced (2.5 mg/kg) locomotor activity in mice and prepulse inhibition in rats (1, 3, or 10 mg/kg). Thus, these findings indicate that MPEP exhibits anxiolytic-like effects and low risks for sedation and psychotomimetic side-effects in rodents. The American Society for Pharmacology and Experimental Therapeutics