Conductive Na/sup +/ transport in an epithelial cell line (LLC-PK/sub 1/) with characteristics of proximal tubular cells

Journal Article · Wed Apr 01 04:00:00 EST 1987 · Am. J. Physiol.; (United States)

OSTI ID:5722330

Cantiello, H F; Scott, J A; Rabito, C A

/sup 22/Na influx and efflux from confluent monolayers of an epithelial cell line with multiple differentiated characteristics of the straight segment of the renal proximal tubule were studied in the presence and absence of a pH gradient. The results show that /sup 22/Na/sup +/ influx in the absence of a pH gradient is inhibited by amiloride as well as by complete replacement of Cl/sup -/ by an impermeable anion, such as isethionate. Dissipation of cell membrane potential by increasing the potassium concentration of the extracellular medium in the presence of valinomycin also inhibited Na/sup +/ influx, whereas sodium influx induced by an H/sup +/ gradient was not affected. Inhibition of Na/sup +/ influx by different maneuvers produced hyperpolarization of the plasma cell membrane, as would be expected if the sodium movement involved net displacement of charges. Calcium and other divalent and trivalent cations also inhibited Na/sup +/ influx measured in the absence of an H/sup +/ gradient. Na/sup +/ influx induced by a pH gradient, however, was not affected. Like the Na/sup +/-H/sup +/-exchange system, the conductive Na/sup +/ pathway is localized in the apical membrane of the epithelial cells. From these results, the authors conclude that at least a fraction of transepithelial Na/sup +/ transport in LLC-PK/sub 1/ monolayers occurs through a simple rheogenic transport system.

• Research Organization: Massachusetts General Hospital, Boston
• OSTI ID: 5722330
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:4; ISSN AJPHA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
ANIMAL CELLS
ANIMAL TISSUES
BARYONS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
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CHLORINE COMPOUNDS
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTROLYTES
ELEMENTARY PARTICLES
EPITHELIUM
FERMIONS
GLYCOSIDES
HADRONS
HALIDES
HALOGEN COMPOUNDS
IN VITRO
IONS
ISOTOPES
KIDNEYS
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ORGANIC COMPOUNDS
ORGANS
OUABAIN
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SODIUM 22
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