Sodium channels in membrane vesicles from cultured toad bladder cells

Journal Article · Fri Apr 01 04:00:00 EST 1988 · American Journal of Physiology; (USA)

OSTI ID:7016308

Asher, C; Moran, A; Rossier, B C; Garty, H ^[1]

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1. Weizmann Institute of Science, Rehovot (Israel) Ben Gurion Univ., Beer-Sheva (Israel) Institut de Pharmacologie de l'Universite de Lausanne (Switzerland)

Electrical potential-driven {sup 22}Na{sup +} fluxes were measured in membrane vesicles prepared from TBM-18(cl23) cells (a clone of the established cell line TB-M). Fifty to seventy percent of the tracer uptake in vesicles derived from cells that were cultivated on a porous support were blocked by the diuretic amiloride. The amiloride inhibition constant was <0.1 {mu}M, indicating that this flux is mediated by the apical Na{sup +}-specific channels. Vesicles prepared from cells that were not grown on a porous support exhibited much smaller amiloride-sensitive fluxes. Two Ca{sup 2+}-dependent processes that down-regulated the channel conductance and were previously identified in native epithelia were found in the cultured cells as well. Vesicles isolated from cells that were preincubated with 5 {times} 10{sup {minus}7} M aldosterone for 16-20 h exhibited higher amiloride-sensitive conductance than vesicles derived from control, steroid-depleted cells. Thus membrane derived from TBM-18(cl23) cells can be used to characterize the epithelial Na{sup +} channel and its hormonal regulation.

• OSTI ID: 7016308
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:4; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ADRENAL HORMONES
ALDEHYDES
ALDOSTERONE
ALKALI METAL ISOTOPES
ALKALINE EARTH METAL COMPOUNDS
AMPHIBIANS
ANIMAL TISSUES
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL EFFECTS
BLADDER
BODY
CALCIUM COMPOUNDS
CELL CULTURES
CORTICOSTEROIDS
DIURETICS
DRUGS
EPITHELIUM
HYDROXY COMPOUNDS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KETONES
KINETICS
LIGHT NUCLEI
MEMBRANE TRANSPORT
MINERALOCORTICOIDS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PREGNANES
RADIOISOTOPES
REACTION KINETICS
SODIUM 22
SODIUM ISOTOPES
STEROIDS
TISSUES
TOADS
UPTAKE
URINARY TRACT
VERTEBRATES
YEARS LIVING RADIOISOTOPES