BACKGROUND: D-Serine, an endogenous agonist of the N-methyl-D-aspartate (NMDA) receptors, is effective in the treatment of schizophrenia. However, orally administered D-serine is metabolized substantially by D-amino acid oxidase (DAAO), diminishing its oral bioavailability. In this study, we examined the effects of oral D-serine administration with or without a DAAO inhibitor, 5-chloro-benzo[d]isoxazol-3-ol (CBIO), on the prepulse inhibition (PPI) deficits after administration of the NMDA receptor antagonist dizocilpine. METHODS: Vehicle or D-serine (30, 300, or 900 mg/kg) with or without CBIO (30 mg/kg) was orally administered to mice 1 hour before administration of dizocilpine (.1 mg/kg), and then the PPI of the acoustic startle response was measured. We measured the extracellular levels of D-serine in the frontal cortex after oral administration of D-serine with or without CBIO. RESULTS: Coadministration of CBIO with D-serine (30 mg/kg), but not D-serine (30 mg/kg) alone, significantly attenuated dizocilpine-induced PPI deficits. Furthermore, coadministration of CBIO significantly increased the extracellular levels of D-serine in the frontal cortex after administration of D-serine. CONCLUSIONS: These findings suggest that coadministration of CBIO significantly enhanced the efficacy of D-serine in attenuating PPI deficits by administration of dizocilpine. Therefore, coadministration of D-serine and a DAAO inhibitor has therapeutic potential for the treatment of schizophrenia.
BACKGROUND:D-Serine, an endogenous agonist of the N-methyl-D-aspartate (NMDA) receptors, is effective in the treatment of schizophrenia. However, orally administered D-serine is metabolized substantially by D-amino acid oxidase (DAAO), diminishing its oral bioavailability. In this study, we examined the effects of oral D-serine administration with or without a DAAO inhibitor, 5-chloro-benzo[d]isoxazol-3-ol (CBIO), on the prepulse inhibition (PPI) deficits after administration of the NMDA receptor antagonist dizocilpine. METHODS: Vehicle or D-serine (30, 300, or 900 mg/kg) with or without CBIO (30 mg/kg) was orally administered to mice 1 hour before administration of dizocilpine (.1 mg/kg), and then the PPI of the acoustic startle response was measured. We measured the extracellular levels of D-serine in the frontal cortex after oral administration of D-serine with or without CBIO. RESULTS: Coadministration of CBIO with D-serine (30 mg/kg), but not D-serine (30 mg/kg) alone, significantly attenuated dizocilpine-induced PPI deficits. Furthermore, coadministration of CBIO significantly increased the extracellular levels of D-serine in the frontal cortex after administration of D-serine. CONCLUSIONS: These findings suggest that coadministration of CBIO significantly enhanced the efficacy of D-serine in attenuating PPI deficits by administration of dizocilpine. Therefore, coadministration of D-serine and a DAAO inhibitor has therapeutic potential for the treatment of schizophrenia.
Authors: Daniel C Javitt; Darryle Schoepp; Peter W Kalivas; Nora D Volkow; Carlos Zarate; Kalpana Merchant; Mark F Bear; Daniel Umbricht; Mihaly Hajos; William Z Potter; Chi-Ming Lee Journal: Sci Transl Med Date: 2011-09-28 Impact factor: 17.956
Authors: James F Berry; Dana V Ferraris; Bridget Duvall; Niyada Hin; Rana Rais; Jesse Alt; Ajit G Thomas; Camilo Rojas; Kenji Hashimoto; Barbara S Slusher; Takashi Tsukamoto Journal: ACS Med Chem Lett Date: 2012-09-16 Impact factor: 4.345
Authors: Pilleriin Sikka; Rosie Walker; Rebecca Cockayne; Matthew J A Wood; Paul J Harrison; Philip W J Burnet Journal: J Neurosci Res Date: 2010-06 Impact factor: 4.164