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 · Tue Mar 01 00:00:00 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), Vol. 254:3; ISSN 0002-9513
• Country of Publication: United States
• Language: English

Related Subjects

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