Basolateral Membrane Na/Base Cotransport Is Dependent on CO2/HCOs in the Proximal Convoluted Tubule
نویسندگان
چکیده
Address reprint requests to Dr. Reto Krapf, Division of Nephroiogy, 1065 HSE, University of California, San Francisco, CA 94143. J. GEN. PSVSlOL. @ The Rockefeller University Press 9 0022-1295/87/12/0833/21 $2.00 833 Volume 90 December 1987 833-853 on July 2, 2017 jgp.rress.org D ow nladed fom 834 T H E JOURNAL OF GENERAL PHYSIOLOGY 9 VOLUME 90 9 1987
منابع مشابه
Basolateral membrane Na/base cotransport is dependent on CO2/HCO3 in the proximal convoluted tubule
The mechanism of basolateral membrane base transport was examined in the in vitro microperfused rabbit proximal convoluted tubule (PCT) in the absence and presence of ambient CO2/HCO3- by means of the microfluorometric measurement of cell pH. The buffer capacity of the cells measured using rapid NH3 washout was 42.8 +/- 5.6 mmol.liter-1.pH unit-1 in the absence and 84.6 +/- 7.3 mmol.liter-1.pH ...
متن کاملBasolateral membrane Na+/H+ antiport, Na+/base cotransport, and Na+-independent Cl-/base exchange in the rabbit S3 proximal tubule.
The basolateral membrane Na+ and Cl(-)-dependent acid-base transport processes were studied in the isolated perfused rabbit S3 proximal straight tubule. Intracellular pH (pHi) was measured with 2'7'-biscarboxyethyl-5,6-carboxyfluorescein (BCECF) and a microfluorometer coupled to the tubule perfusion apparatus. Reduction of basolateral HCO3- from 25 to 5 mM caused pHi to decrease at a rate of 0....
متن کاملEffects of acetazolamide on Na+-HCO-3 cotransport in basolateral membrane vesicles isolated from rabbit renal cortex.
We evaluated the effects of acetazolamide on Na+-HCO3- cotransport in basolateral membrane vesicles isolated from the rabbit renal cortex. Na+ uptake stimulated by an imposed inward HCO3- gradient was not significantly reduced by 1.2 mM acetazolamide, indicating that acetazolamide does not directly inhibit Na+-HCO3- cotransport. 4,4'-Diisothiocyanostilbene-2,2'-disulfonate (DIDS)-sensitive Na+-...
متن کاملChange of apparent stoichiometry of proximal-tubule Na(+)-HCO3- cotransport upon experimental reversal of its orientation.
Electrogenic cotransport of Na+ with HCO3- has been reported in numerous tissues. It has always been shown with a net transfer of negative charge, but in some situations achieves net outward transport of both species with a stoichiometry of at least three HCO3- ions per Na+ ion (3:1), and in other situations achieves net inward transport of both species and has a stoichiometry of at most two HC...
متن کاملRenal Na(+)-glucose cotransporters.
In humans, the kidneys filter approximately 180 g of D-glucose from plasma each day, and this is normally reabsorbed in the proximal tubules. Although the mechanism of reabsorption is well understood, Na(+)-glucose cotransport across the brush-border membrane and facilitated diffusion across the basolateral membrane, questions remain about the identity of the genes responsible for cotransport a...
متن کامل