title: Chronic morphine treatment increases the expression of vesicular glutamate transporter 1 in the mouse spinal cord.
abstract: Long-term exposure to morphine results in tolerance to morphine-induced antinociception. Here, we found that mice tolerant to morphine exhibited the significant increase in the protein levels of the vesicular glutamate transporter 1 and the synaptic vesicle-specific small G protein Rab3A, but not vesicular glutamate transporter 2 and vesicular gamma-aminobutyric acid transporter. These findings suggest that repeated treatment with morphine enhances excitatory synaptic transmission in the spinal cord, and in turn suppresses the morphine-induced antinociception.
authors.affiliation: Department of Toxicology, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Shinagawa-ku, Tokyo, 142-8501, Japan.
authors.forename: Masami
authors.initials: M
authors.lastname: Suzuki
authors.forename: Minoru
authors.initials: M
authors.lastname: Narita
authors.forename: Michiko
authors.initials: M
authors.lastname: Narita
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Suzuki
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D015151:Immunoblotting; D007279:Injections, Subcutaneous; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D021122:Protein Subunits / Q000378:metabolism; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013116:Spinal Cord / Q000187:drug effects* / Q000378:metabolism; D050598:Vesicular Glutamate Transport Protein 1 / Q000378:metabolism*; D050599:Vesicular Glutamate Transport Protein 2; D050495:Vesicular Inhibitory Amino Acid Transport Proteins / Q000378:metabolism; D020826:rab3A GTP-Binding Protein / Q000378:metabolism
chemical_list: D000701:Analgesics, Opioid; C409466:NR1 NMDA receptor; D021122:Protein Subunits; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D050598:Vesicular Glutamate Transport Protein 1; D050599:Vesicular Glutamate Transport Protein 2; D050495:Vesicular Inhibitory Amino Acid Transport Proteins; C492244:Viaat protein, mouse; D009020:Morphine; D020826:rab3A GTP-Binding Protein