Anion exchange pathways for Cl sup minus transport in rabbit renal microvillus membranes

Journal Article · Tue Sep 01 00:00:00 EDT 1987 · American Journal of Physiology; (USA)

OSTI ID:5030260

Karniski, L P; Aronson, P S ^[1]

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1. Univ. of Iowa, Iowa City (USA) Yale School of Medicine, New Haven, CT (USA)

The authors evaluated the mechanisms of chloride transport in microvillus membrane vesicles isolated from the rabbit renal cortex. The presence of Cl-formate exchange was confirmed. Outward gradients of oxaloacetate, HCO{sub 3}, acetate, lactate, succinate, sulfate, and p-aminohippurate (PAH) stimulated the rate of Cl uptake minimally or not at all. However, an outward gradient of oxalate stimulated Cl uptake by 70%, and an outward Cl gradient induced uphill oxalate uptake, indicting Cl-oxalate exchange. Moreover, an outward formate gradient induced uphill oxalate uptake, indicating formate-oxalate exchange. Studies of inhibitor and substrate specificity indicated the probably operation of at least two separate anion exchangers in mediating Cl transport. The Cl-formate exchanger accepted Cl and formate as substrates, had little or no affinity for oxalate, was sensitive to inhibition by furosemide, and was less sensitive to inhibition by 4,4{prime}-diisothiocyanostilbene-2,2{prime}-disulfonic acid (DIDS). The Cl (formate)-oxalate exchanger also accepted Cl and formate as substrates but had high affinity for oxalate, was highly sensitive to inhibition by DIDS, and was less sensitive to inhibition by furosemide. The Cl-formate exchanger was electroneutral, whereas the Cl (formate)-oxalate exchanger was electrogenic. They conclude that at least separate anion exchangers mediating Cl transport are present on the luminal membrane of the rabbit proximal tubule cell. These exchangers may play important roles in mediating transtubular Cl and oxalate transport in this nephron segment.

• OSTI ID: 5030260
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 253:3; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID CARBONATES
ANIMALS
ANIONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CARBON 14 COMPOUNDS
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
CHARGED PARTICLES
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DICARBOXYLIC ACIDS
ELECTRON CAPTURE RADIOISOTOPES
HALIDES
HALOGEN COMPOUNDS
HYDROXY ACIDS
IONS
ISOTOPES
KIDNEYS
KINETICS
LABELLED COMPOUNDS
LACTIC ACID
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANS
OXALATES
PHYSIOLOGY
RABBITS
RADIOISOTOPES
REACTION KINETICS
SUCCINIC ACID
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES