A nucleoside sensitive organic cation transporter in opossum kidney
cells.
Chen, Rong, Bih Fang Pan, Mamoru Sakurai, and J. Arly Nelson.
Department of Experimental Pediatrics and The Graduate School of
Biomedical Sciences, The University of Texas M. D. Anderson Cancer
Center, Houston, TX 77030
APStracts 5:0208F, 1998.
Renal secretion of organic cations and anions are pleiotropic, active
processes in mammals. Some nucleosides such as deoxyadenosine (dAdo),
2-chlorodeoxyadenosine and azidothymidine are secreted by human and
rodent kidneys. Previous work (Biochemical Pharmacology 32: 2323,
1983) indicated a role for the classical organic cation transporter
(OCT) in the secretion of the dAdo analog, 2_-deoxytubercidin (dTub),
by mouse kidney. Using [14C]-tetraethylammonium bromide (TEA) as a
substrate, we tested several renal cell lines for a nucleoside
-sensitive OCT. American opossum kidney proximal tubule cells (OK)
express a cimetidine-sensitive and metabolic-dependent ability to
efflux TEA. Other classical OCT inhibitors and several nucleosides
also inhibit TEA efflux by these cells in a manner reflecting
structural specificity for the carrier. Inhibition of OCT by
nucleosides is not a universal feature of OCTs since TEA transport
mediated by cloned rat kidney OCT2 in the Xenopus laevis oocyte
system was not inhibited by the same nucleosides. In conclusion, OK
cells appear to possess an OCT that may also transport some
nucleosides by a novel carrier.
Received 12 May 1998; accepted in final form 17 November 1998.
APS Manuscript Number F113-8.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 9 December 1998