Pawlik, M.J.; Aldana, B.I.; Belfiori-Carrasco, L.F.; Obara-Michlewska, M.; Popek, M.P.; Czarnecka, A.M.; Albrecht, J. Inhibition of Glutamate Release, but Not of Glutamine Recycling to Glutamate, Is Involved in Delaying the Onset of Initial Lithium-Pilocarpine-Induced Seizures in Young Rats by a Non-Convulsive MSO Dose. Int. J. Mol. Sci. 2021, 22, 11127. https://doi.org/10.3390/ijms222011127
Pawlik, M.J.; Aldana, B.I.; Belfiori-Carrasco, L.F.; Obara-Michlewska, M.; Popek, M.P.; Czarnecka, A.M.; Albrecht, J. Inhibition of Glutamate Release, but Not of Glutamine Recycling to Glutamate, Is Involved in Delaying the Onset of Initial Lithium-Pilocarpine-Induced Seizures in Young Rats by a Non-Convulsive MSO Dose. Int. J. Mol. Sci. 2021, 22, 11127. https://doi.org/10.3390/ijms222011127
Pawlik, M.J.; Aldana, B.I.; Belfiori-Carrasco, L.F.; Obara-Michlewska, M.; Popek, M.P.; Czarnecka, A.M.; Albrecht, J. Inhibition of Glutamate Release, but Not of Glutamine Recycling to Glutamate, Is Involved in Delaying the Onset of Initial Lithium-Pilocarpine-Induced Seizures in Young Rats by a Non-Convulsive MSO Dose. Int. J. Mol. Sci. 2021, 22, 11127. https://doi.org/10.3390/ijms222011127
Pawlik, M.J.; Aldana, B.I.; Belfiori-Carrasco, L.F.; Obara-Michlewska, M.; Popek, M.P.; Czarnecka, A.M.; Albrecht, J. Inhibition of Glutamate Release, but Not of Glutamine Recycling to Glutamate, Is Involved in Delaying the Onset of Initial Lithium-Pilocarpine-Induced Seizures in Young Rats by a Non-Convulsive MSO Dose. Int. J. Mol. Sci. 2021, 22, 11127. https://doi.org/10.3390/ijms222011127
Abstract
Pretreatment with non-convulsive dose of methionine sulfoximine (MSO) attenuated lithi-um-pilocarpine-induced (Li-Pilo) seizures in young rats [1]. We hypothesized that the effect of MSO results from a) glutamine synthetase block-mediated inhibition of conversion of Glu/Gln precursors to neurotransmitter Glu, and/or from b) altered synaptic Glu release. Pilo was admin-istered 60 min prior to sacrifice, MSO at 75 mg/kg, i.p., 2.5 h earlier. [1,2-13C]acetate and [U-13C]glucose were i.p.-injected either together with Pilo (onset) or 15 min before sacrifice (final phase). Their conversion to Glu and Gln in hippocampus and entorhinal cortex was followed us-ing [13C] gas chromatography-mass spectrometry. Release of in vitro loaded [3H]D-Asp from ex vi-vo brain slices was measured in continuously collected superfusates. Protein and mRNA expres-sion were measured by Western Blot and real-time PCR techniques, respectively. At no time point nor brain region did MSO modify incorporation of [13C] to Glu or Gln in Pilo-treated rats. MSO pretreatment decreased by ~37% high potassium-induced [3H]D-Asp release and reduced by ~50% the synaptic vesicular Glu transporter VGLUT1 protein, but not mRNA content in the hippo-campus. The results indicate that MSO at non-convulsive dose mitigates the initial Pilo-induced seizures by interfering with synaptic Glu-release but not with neurotransmitter Glu recycling.
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