Aldosterone increases the apical Na sup + permeability of toad bladder by two different mechanisms
- Weizmann Institute of Science, Rehovot (Israel)
The aldosterone-induced augmentation of Na{sup +} transport in toad bladder was analyzed by comparing the hormonal actions on the transepithelial short-circuit current and on the amiloride-sensitive {sup 22}Na{sup +} uptake in isolated membrane vesicles. Incubating bladders with 0.5 {mu}M aldosterone for 3 hr evoked more than a 2-fold increase of the short-circuit current but had no effect on the amiloride-sensitive Na{sup +} transport in apical vesicles derived from the treated tissue. A longer incubation produced an additional augmentation of the short-circuit current, which was accompanied by about a 3-fold increase of the channel activity in isolated membranes. The stimulatory effect of aldosterone sustained in vesicles was inhibited by the antagonist spironolactone and the protein synthesis inhibitor cycloheximide. It is suggested that aldosterone elevates the apical Na{sup +} permeability of target epithelia by two different mechanisms: a relatively fast effect which is insensitive to triiodothyronine or butyrate and is not sustained by the isolated membrane, and a slower or later response blocked by these reagents, which is preserved by the isolated membrane. The data also indicate that these processes are mediated by different nuclear receptors.
- OSTI ID:
- 5602156
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 85:19; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
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ALDOSTERONE
BIOCHEMISTRY
BLADDER
PERMEABILITY
MEMBRANE TRANSPORT
PHYSIOLOGY
RUBIDIUM 86
UPTAKE
SODIUM 22
CELL MEMBRANES
SODIUM CHLORIDES
TOADS
ADRENAL HORMONES
ALDEHYDES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
AMPHIBIANS
ANIMALS
AQUATIC ORGANISMS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CELL CONSTITUENTS
CHEMISTRY
CHLORIDES
CHLORINE COMPOUNDS
CORTICOSTEROIDS
DAYS LIVING RADIOISOTOPES
HALIDES
HALOGEN COMPOUNDS
HYDROXY COMPOUNDS
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
KETONES
LIGHT NUCLEI
MEMBRANES
MINERALOCORTICOIDS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PREGNANES
RADIOISOTOPES
RUBIDIUM ISOTOPES
SODIUM COMPOUNDS
SODIUM ISOTOPES
STEROIDS
URINARY TRACT
VERTEBRATES
YEARS LIVING RADIOISOTOPES
551001* - Physiological Systems- Tracer Techniques