Nitric oxide-evoked [3H]taurine release is mediated by reversal of the Na(+)-dependent carrier-mediated taurine transport system.
The pharmacological characteristics of [3H]taurine release evoked by nitric oxide (NO) were investigated using mouse cerebral cortical neurons in primary culture. N-Methyl-D-aspartate (NMDA) and S-nitroso-N-acetylpenicillamine (SNAP) dose-dependently increased [3H]taurine release from neurons. The NMDA-evoked release of [3H]taurine was reduced to the basal level by N omega-nitro-L-arginine, a NO synthase inhibitor, and MK-801, a noncompetitive antagonist for NMDA receptors. The NMDA- and SNAP-evoked releases of [3H]taurine were completely abolished by hemoglobin, indicating that these [3H]taurine releases were evoked by NO produced by NMDA receptor activation and liberated from SNAP. Withdrawal of Na+ from incubation buffer significantly inhibited the NMDA- and SNAP-induced [3H]taurine releases, whereas removal of Ca2+ produced no alteration in the SNAP-evoked [3H]taurine release. In addition, beta-alanine and guanidinoethane sulfonate, antitransporters of the carrier-mediated taurine transport system, reduced the NMDA- and SNAP-evoked releases of [3H]taurine in a dose-dependent manner. These results indicate that the NO-evoked [3H]taurine release from cerebral cortical neurons is mediated by a reversal of the Na(+)-dependent carrier-mediated taurine transport system.
Department of Pharmacology, Kyoto Prefectural University of Medicine, Japan.
S
S
Ohkuma
M
M
Katsura
D Z
DZ
Chen
K
K
Kuriyama
D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000378:metabolism*; D016291:Dizocilpine Maleate / Q000494:pharmacology; D005333:Fetus; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000378:metabolism*; D026901:Membrane Transport Proteins; D051379:Mice; D008815:Mice, Inbred Strains; D016202:N-Methylaspartate / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology*; D010396:Penicillamine / Q000031:analogs & derivatives / Q000494:pharmacology; D016194:Receptors, N-Methyl-D-Aspartate / Q000502:physiology; D026423:S-Nitroso-N-Acetylpenicillamine; D012964:Sodium / Q000494:pharmacology; D013654:Taurine / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D014316:Tritium; D015091:beta-Alanine / Q000494:pharmacology; D000099247:Taurine Transporters
D002352:Carrier Proteins; D016291:Dizocilpine Maleate; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D016202:N-Methylaspartate; D009569:Nitric Oxide; D019335:Nitroarginine; D010396:Penicillamine; D016194:Receptors, N-Methyl-D-Aspartate; D026423:S-Nitroso-N-Acetylpenicillamine; D012964:Sodium; D013654:Taurine; D014316:Tritium; D015091:beta-Alanine; D000099247:Taurine Transporters; C009558:taurocyamine