title: Functional impairment of rat taurine transporter by activation of nitrogen oxide through superoxide.
abstract: The objective of this study was to identify the nitrogen oxide form(s) involved in the functional impairment of the rat taurine transport system. Taurine uptake activity in the rat renal brush border membrane vesicle (RBBMV) preparation or Xenopus laevis oocytes that express the rat taurine transporter was compared after the pretreatment with nitrogen oxide donors from which nitric oxide (NO) is released at different rates. The functional impairment was associated with a reduced Vmax, but did not involve an alteration in the Km, of taurine uptake in the RBBMV preparation that had been pretreated with sodium nitroprusside, a slow release nitric oxide (NO) donor. When the preparation was pretreated with S-nitroso-N-acetyl penicillamine, a rapid release NO donor, the activity of taurine uptake was unaffected. The activity was not statistically different from the control after the pretreatment with sodium nitroprusside and superoxide dismutase. Consistent with the study with RBBMV, a similar alteration in the activity of taurine uptake by NO donors was observed in oocytes expressing the transporter. Considering the fact that peroxynitrite, a highly reactive nitrogen oxide form, is formed by the reaction between NO and superoxide, the taurine transporter, and probably other transport systems as well, may be functionally impaired by peroxynitrite.
authors.affiliation: Life Science R&D Park, SK Biopharmaceuticals Co., Ltd., Daejeon, Korea.
authors.forename: Tae-Sung
authors.initials: TS
authors.lastname: Koo
authors.forename: Hyun-Jung
authors.initials: HJ
authors.lastname: Kwon
authors.forename: Mi-Hwa
authors.initials: MH
authors.lastname: Kim
authors.forename: Dae-Duk
authors.initials: DD
authors.lastname: Kim
authors.forename: Chang-Koo
authors.initials: CK
authors.lastname: Shim
authors.forename: Suk-Jae
authors.initials: SJ
authors.lastname: Chung
authors.forename: Saeho
authors.initials: S
authors.lastname: Chong
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002478:Cells, Cultured; D005260:Female; D007672:Kidney Cortex / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D008562:Membrane Glycoproteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism; D049990:Membrane Transport Modulators / Q000494:pharmacology; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D009589:Nitrogen Oxides / Q000378:metabolism; D009599:Nitroprusside / Q000494:pharmacology; D009865:Oocytes / Q000187:drug effects / Q000378:metabolism; D030421:Peroxynitrous Acid / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D013481:Superoxides / Q000378:metabolism*; D013654:Taurine / Q000378:metabolism*; D014982:Xenopus laevis; D000099247:Taurine Transporters
chemical_list: D008562:Membrane Glycoproteins; D049990:Membrane Transport Modulators; D026901:Membrane Transport Proteins; D009569:Nitric Oxide; D020030:Nitric Oxide Donors; D009589:Nitrogen Oxides; D009599:Nitroprusside; D030421:Peroxynitrous Acid; D011994:Recombinant Proteins; D026423:S-Nitroso-N-Acetylpenicillamine; D013481:Superoxides; D013654:Taurine; D000099247:Taurine Transporters