title: Functional characterisation of nucleoside transport in rat brain endothelial cells.
abstract: Multiple nucleoside transport systems exist in the body yet the subtypes functional at the blood-brain barrier (BBB) have not been fully investigated. We have employed RBE4 immortalised rat brain endothelial cells to functionally identify the carrier subtypes involved in nucleoside transfer between blood and brain. Uptake in RBE4 cells was partially sodium dependent, indicating the presence of both equilibrative and concentrative systems. Uptake of adenosine via equilibrative transporters was sensitive to nitro-benzylmercaptopurine riboside, which showed biphasic inhibition. Uptake of [3H]-adenosine via concentrative transporters was studied using the subtype-specific inhibitors thymidine (cit), formycin-B (cif) and tubercidin (cib) and was significantly reduced by thymidine and formycin-B but not by tubercidin. This study suggests that nucleoside transport at the in situ BBB may be mediated by ei and es equilibrative transporters and by cit and cif concentrative transporters.
authors.affiliation: Blood-Brain Barrier Research Group, Centre for Neuroscience Research, GKT School of Biomedical Sciences, King's College London, UK.
authors.forename: Mansoor
authors.initials: M
authors.lastname: Chishty
authors.forename: David J
authors.initials: DJ
authors.lastname: Begley
authors.forename: N Joan
authors.initials: NJ
authors.lastname: Abbott
authors.forename: Andreas
authors.initials: A
authors.lastname: Reichel
mesh_terms: D000818:Animals; D001692:Biological Transport / Q000502:physiology; D001812:Blood-Brain Barrier / Q000502:physiology; D001921:Brain / Q000378:metabolism*; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004730:Endothelium, Vascular / Q000378:metabolism*; D009705:Nucleosides / Q000378:metabolism*; D051381:Rats
chemical_list: D009705:Nucleosides