Cl- transport in basolateral renal medullary vesicles: I. Cl- transport in intact vesicles.
This paper provides the results of studies which characterized conductive 36Cl- flux in basolaterally enriched membrane vesicles prepared from rabbit renal outer medulla. Conductive 36Cl- uptake was studied under two different experimental conditions. In the first, 36Cl- flux was driven by an inside positive voltage created with oppositely directed Cl- and gluconate gradients. In the second, an inwardly direct K+ gradient was used to drive 36Cl- uptake. By these two methods, voltage-sensitive 36Cl- uptake was shown to comprise about 45 and 65%, respectively, of the initial rates of total 36Cl- flux. Separate paired studies demonstrated that the conductive 36Cl- uptake was inhibited by the Cl- channel blocker diphenylamine-2-carboxylate (DPC) with an IC50 for DPC of 154 microM. The voltage-dependent 36Cl- uptake had an activation energy of 6.4 kcal/mole. This 36Cl- conductance had an anion selectivity sequence of I- greater than Cl- greater than or equal to NO3- much greater than gluconate.
Bayliss
J M
JM
Department of Internal Medicine, University of Arkansas College of Medicine, Little Rock 72205.
Reeves
W B
WB
Andreoli
T E
TE
D000818:Animals; D000838:Anions / Q000378:metabolism; D001692:Biological Transport / Q000187:drug effects; D002712:Chlorides / Q000378:metabolism*; D004594:Electrophysiology; D007679:Kidney Medulla / Q000378:metabolism*; D007700:Kinetics; D011817:Rabbits; D013696:Temperature; D062367:ortho-Aminobenzoates / Q000494:pharmacology
D000838:Anions; D002712:Chlorides; D062367:ortho-Aminobenzoates; C001209:fenamic acid