title: Swelling-activated taurine and creatine effluxes from rat cortical astrocytes are pharmacologically distinct.
abstract: Primary cultures of rat cortical astrocytes undergo a swelling-activated loss of taurine and creatine. In this study, the pharmacological characteristics of the taurine and creatine efflux pathways were compared, and significant differences were shown to exist between the two. Both taurine and creatine effluxes were rapidly activated upon exposure of astrocytes to hypo-osmotic media, and rapidly inactivated upon their return to iso-osmotic media. The relative rates of taurine and creatine efflux depended upon the magnitude of the hypo-osmotic shock. Anion-transport inhibitors strongly inhibited taurine efflux, with the order of potency being NPPB > DIDS > niflumic acid. DIDS and NPPB had less of an inhibitory effect on creatine efflux, whereas tamoxifen and niflumic acid actually stimulated creatine efflux. These data are consistent with separate pathways for taurine and creatine loss during astrocyte swelling.
authors.affiliation: MRC Biochemical and Clinical Magnetic Resonance Unit, Department of Biochemistry, University of Oxford, South Parks Rd., Oxford 3QU, UK.
authors.forename: J H
authors.initials: JH
authors.lastname: Bothwell
authors.forename: P
authors.initials: P
authors.lastname: Styles
authors.forename: K K
authors.initials: KK
authors.lastname: Bhakoo
mesh_terms: D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D000838:Anions / Q000378:metabolism; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D001692:Biological Transport; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D003401:Creatine / Q000378:metabolism*; D009579:Nitrobenzoates / Q000494:pharmacology; D027361:Organic Anion Transporters / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009997:Osmotic Pressure; D051381:Rats; D013654:Taurine / Q000378:metabolism*; D013997:Time Factors
chemical_list: D000838:Anions; D009579:Nitrobenzoates; D027361:Organic Anion Transporters; D013654:Taurine; C058176:5-nitro-2-(3-phenylpropylamino)benzoic acid; D003401:Creatine; D017878:4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid