RATIONALE: It was recently reported that administration of the metabotropic glutamate 2 and 3 (mGlu2/3) receptor agonist prodrug LY2140023 to schizophrenic patients decreased positive symptoms. However, at the single, potentially suboptimal, dose that was tested, LY2140023 trended towards being inferior to olanzapine on several indices of efficacy within the Positive and Negative Syndrome Scale. OBJECTIVES: In this study, we examined whether the antipsychotic potential of mGlu2/3 receptor agonism can be enhanced with 5-HT(2A) receptor antagonism. MATERIALS AND METHODS: Specifically, we characterized the effects of co-administering submaximally effective doses of the 5-HT(2A) receptor antagonist M100907 (0.2 mg/kg) and the mGlu2/3 receptor agonist LY379268 (1 mg/kg) on amphetamine-induced and MK-801-induced psychomotor activity in rats, an assay sensitive to antipsychotics. We also determined the effects of co-administering these two compounds on MK-801-induced dopamine and norepinephrine efflux in the nucleus accumbens (NAc). RESULTS: At the submaximally effective doses tested, the effects of M100907 and LY379268 on amphetamine-induced and MK-801-induced psychomotor activity were significantly greater when given together than when given separately. Furthermore, coadministration of these doses of M100907 and LY379268 reduced MK-801-induced dopamine efflux in the NAc. This effect on dopamine release was not observed with the administration of either compound alone, even at higher doses that attenuated MK-801-induced psychomotor activity. CONCLUSIONS: Our results suggest that a single compound having both mGlu2/3 receptor agonist and 5-HT(2A) receptor antagonist activity, or coadministration of two compounds selective for these receptors, could be superior in terms of efficacy and/or reduced side-effect liability relative to an mGlu2/3 receptor agonist alone.
RATIONALE: It was recently reported that administration of the metabotropic glutamate 2 and 3 (mGlu2/3) receptor agonist prodrug LY2140023 to schizophrenicpatients decreased positive symptoms. However, at the single, potentially suboptimal, dose that was tested, LY2140023 trended towards being inferior to olanzapine on several indices of efficacy within the Positive and Negative Syndrome Scale. OBJECTIVES: In this study, we examined whether the antipsychotic potential of mGlu2/3 receptor agonism can be enhanced with 5-HT(2A) receptor antagonism. MATERIALS AND METHODS: Specifically, we characterized the effects of co-administering submaximally effective doses of the 5-HT(2A) receptor antagonist M100907 (0.2 mg/kg) and the mGlu2/3 receptor agonist LY379268 (1 mg/kg) on amphetamine-induced and MK-801-induced psychomotor activity in rats, an assay sensitive to antipsychotics. We also determined the effects of co-administering these two compounds on MK-801-induced dopamine and norepinephrine efflux in the nucleus accumbens (NAc). RESULTS: At the submaximally effective doses tested, the effects of M100907 and LY379268 on amphetamine-induced and MK-801-induced psychomotor activity were significantly greater when given together than when given separately. Furthermore, coadministration of these doses of M100907 and LY379268 reduced MK-801-induced dopamine efflux in the NAc. This effect on dopamine release was not observed with the administration of either compound alone, even at higher doses that attenuated MK-801-induced psychomotor activity. CONCLUSIONS: Our results suggest that a single compound having both mGlu2/3 receptor agonist and 5-HT(2A) receptor antagonist activity, or coadministration of two compounds selective for these receptors, could be superior in terms of efficacy and/or reduced side-effect liability relative to an mGlu2/3 receptor agonist alone.
Authors: Daniel S Lorrain; Hervé Schaffhauser; Una C Campbell; Christopher S Baccei; Lucia D Correa; Blake Rowe; Dana E Rodriguez; Jeffery J Anderson; Mark A Varney; Anthony B Pinkerton; Jean-Michel Vernier; Linda J Bristow Journal: Neuropsychopharmacology Date: 2003-06-25 Impact factor: 7.853
Authors: Miguel Fribourg; José L Moreno; Terrell Holloway; Davide Provasi; Lia Baki; Rahul Mahajan; Gyu Park; Scott K Adney; Candice Hatcher; José M Eltit; Jeffrey D Ruta; Laura Albizu; Zheng Li; Adrienne Umali; Jihyun Shim; Alexandre Fabiato; Alexander D MacKerell; Vladimir Brezina; Stuart C Sealfon; Marta Filizola; Javier González-Maeso; Diomedes E Logothetis Journal: Cell Date: 2011-11-23 Impact factor: 41.582
Authors: Manoranjan S D'Souza; Matthias E Liechti; Ana M Ramirez-Niño; Ronald Kuczenski; Athina Markou Journal: Neuropsychopharmacology Date: 2011-06-08 Impact factor: 7.853
Authors: Joanna M Wierońska; Francine C Acher; Anna Sławińska; Piotr Gruca; Magdalena Lasoń-Tyburkiewicz; Mariusz Papp; Andrzej Pilc Journal: Psychopharmacology (Berl) Date: 2013-03-10 Impact factor: 4.530