Cl sup minus -HCO sub 3 sup minus exchange is present with Na sup + -K sup + -Cl sup minus cotransport in rabbit parotid acinar basolateral membranes

Journal Article · Mon Feb 29 23:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:6948781

Turner, R J; George, J N ^[1]

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1. National Institutes of Health, Bethesda, MD (USA)

The presence of a sodium-independent electroneutral Cl{sup {minus}}-anion exchanger in a basolateral membrane vesicle preparation from the rabbit parotid is demonstrated. This exchanger is shared by HCO{sub 3}{sup {minus}}, NO{sub 3}{sup {minus}}, Br{sup {minus}}, F{sup {minus}}, and formate, but not by thiocyanate, acetate, methylsulfate, gluconate, or hydroxyl ions. In order of relative potency, the exchanger is inhibited by SITS {ge} phloretin > furosemide > bumetanide {ge} phlorizin. A Na{sup +}-K{sup +}-dependent component of chloride flux, presumably due to the Na{sup +}-K{sup +}-Cl{sup {minus}} cotransporter already characterized in this preparation, was also observed. {sup 36}Cl uptake into vesicles loaded with KCl exhibited an overshoot of intravesicular ({sup 36}Cl) due to {sup 36}Cl-Cl exchange. However, when vesicles were loaded with both KCl and NaCl the height of the overshoot was considerably decreased indicating a Na{sup +}-K{sup +}-dependent dissipation of the intravesicular to extravesicular chloride gradient. This experiment provides strong evidence that the Na{sup +}-K{sup +}Cl{sup {minus}} cotransporter and the Cl{sup {minus}} HCO{sub 3}{sup {minus}} exchange are present in the same membrane vesicles. These results indicate that Cl{sup {minus}}-HCO{sub 3}{sup {minus}} exchange is present in the basolateral membrane of parotid acinar cells and thus that this transporter may play a significant role in salivary secretion.

• OSTI ID: 6948781
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:3; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID CARBONATES
ALKALI METAL COMPOUNDS
ANIMAL TISSUES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
CELL CONSTITUENTS
CELL MEMBRANES
CHARGED PARTICLES
CHLORIDES
CHLORINE 36
CHLORINE COMPOUNDS
CHLORINE ISOTOPES
DIURETICS
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
EPITHELIUM
GLANDS
HALIDES
HALOGEN COMPOUNDS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INORGANIC ACIDS
IONS
ISOTOPES
KINETICS
LIGHT NUCLEI
MEMBRANE TRANSPORT
MEMBRANES
NUCLEI
ODD-ODD NUCLEI
ORGANS
POTASSIUM CHLORIDES
POTASSIUM COMPOUNDS
RADIOISOTOPES
REACTION KINETICS
SALIVARY GLANDS
SECRETION
SODIUM CHLORIDES
SODIUM COMPOUNDS
TISSUES
YEARS LIVING RADIOISOTOPES