Stimulation of chloride transport by HCO/sub 3/-CO/sub 2/ in rabbit cortical collecting tubule

Journal Article · Tue Jul 01 04:00:00 EDT 1986 · Am. J. Physiol.; (United States)

OSTI ID:6788348

Tago, K; Schuster, V L; Stokes, J B

The authors examined both the role of HCO/sub 3/-CO/sub 2/ in Cl transport as well as the effect of in vivo acid-base status on Cl transport by the rabbit cortical collecting tubule. The lumen-to-bath /sup 36/Cl tracer flux, expressed as the rate coefficient K/sub Cl/, was measured in either HEPES-buffered (CO/sub 2/-free) or HCO/sub 3/-CO/sub 2/-containing solutions. Amiloride was added to the perfusate to minimize the transepithelial voltage and thus the electrical driving force for Cl diffusion. Because K/sub Cl/ fell spontaneously with time in HCO/sub 3/-CO/sub 2/ solutions in the absence but not the presence of cAMP, they used cAMP throughout to avoid time-dependent changes. Acute in vitro removal of bath HCO/sub 3/-CO/sub 2/ reduced K/sub Cl/. Acetazolamide addition in HEPES-buffered solutions also lowered K/sub Cl/; K/sub Cl/ could be restored to control values by adding exogenous HCO/sub 3/-CO/sub 2/ in the presence of acetazolamide. In vivo acid-base effects on Cl transport were determined by dissecting tubules from either NaHCO/sub 3/-loaded or NH/sub 4/Cl-loaded rabbits. Most of this effect of HCO/sub 3/-CO/sub 2/ addition on K/sub Cl/ could not be accounted for by Cl-HCO/sub 3/ exchange; rather, it appeared due to stimulation of Cl self exchange. The data are consistent with /sup 36/Cl transport occurring via Cl-HCO/sub 3/ exchange as well as Cl self exchange. Both processes are acutely stimulated by HCO/sub 3/ and/or CO/sub 2/, and both are chronically regulated by in vivo acid-base status.

• Research Organization: Univ. of Iowa, Iowa City
• OSTI ID: 6788348
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 251:1; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBON COMPOUNDS
CARBON DIOXIDE
CARBON OXIDES
CARBONATES
CHALCOGENIDES
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
HALIDES
HALOGEN COMPOUNDS
ION EXCHANGE
ISOTOPES
KIDNEYS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
ODD-ODD NUCLEI
ORGANS
OXIDES
OXYGEN COMPOUNDS
PHYSIOLOGY
RABBITS
RADIOISOTOPES
TUBULES
VERTEBRATES
YEARS LIVING RADIOISOTOPES