title: Na(+)-dependent, concentrative nucleoside transport in rat macrophages. Specificity for natural nucleosides and nucleoside analogs, including dideoxynucleosides, and comparison of nucleoside transport in rat, mouse and human macrophages.
abstract: The effects of natural nucleosides and various analogs thereof on Na(+)-dependent, concentrative transport of formycin B by cultured rat macrophages were investigated. Concentrative transport is the sole nucleoside transport system of these cells. The results indicated that uridine, 5'-fluorouridine, all natural purine nucleosides, 2-chloroadenosine and 5'-deoxyadenosine are efficient substrates for the transporter. None of nine other pyrimidine nucleosides was transported. 3'-Deoxy-adenosine, 2',3'-dideoxyadenosine, 8-azidoadenosine, tubercidin, 5'-methylthioadenosine 6-mercaptopurine riboside and adenosine arabinoside were either poor substrates or not transported significantly. The substrate activity of some of the natural nucleosides and the lack of substrate activity of 3'-deoxyadenosine, 2',3'-dideoxyadenosine, 8-azidoadenosine and 2',3'-dideoxycytidine were confirmed by direct uptake measurements. No significant concentrative nucleoside transport was detected in cultured human monocytes/macrophages, whereas mouse macrophages possessed both concentrative and equilibrative nucleoside transporters.
authors.affiliation: Department of Microbiology, Medical School, University of Minnesota, Minneapolis 55455.
authors.forename: P G
authors.initials: PG
authors.lastname: Plagemann
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D002352:Carrier Proteins / Q000378:metabolism; D002478:Cells, Cultured; D015224:Dideoxynucleosides / Q000378:metabolism*; D004176:Dipyridamole / Q000494:pharmacology; D005573:Formycins / Q000378:metabolism; D006801:Humans; D008264:Macrophages / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D033703:Nucleoside Transport Proteins; D011684:Purine Nucleosides / Q000494:pharmacology*; D011741:Pyrimidine Nucleosides / Q000494:pharmacology*; D051381:Rats; D012964:Sodium / Q000494:pharmacology*; D013379:Substrate Specificity
chemical_list: D002352:Carrier Proteins; D015224:Dideoxynucleosides; D005573:Formycins; D008565:Membrane Proteins; D033703:Nucleoside Transport Proteins; D011684:Purine Nucleosides; D011741:Pyrimidine Nucleosides; C034561:formycin B; D004176:Dipyridamole; D012964:Sodium