cAMP-associated inhibition of Na/sup +/-H/sup +/ exchanger in rabbit kidney brush-border membranes

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

OSTI ID:6409533

Weinman, E J; Shenolikar, S; Kahn, A M

Adenosine 3',5'-cyclic monophosphate (cAMP) inhibits the rate of bicarbonate reabsorption and the rate of Na/sup +/-H/sup +/ exchange transport in the apical membrane of the proximal convoluted tubule. To study the relation between cAMP, cAMP-dependent protein kinase, and Na/sup +/-H/sup +/ exchange transport, brush-border membrane vesicles from the rabbit kidney were phosphorylated in vitro. The rate of proton gradient-stimulated amiloride-inhibitable /sup 22/Na/sup +/ uptake was measured as an index of Na/sup +/-H/sup +/ exchange transport activity. The inclusion of cAMP (10/sup -6/ M) in a phosphorylating solution containing ATP decreased the 10-s uptake of amiloride-sensitive sodium from 2.25 +/-0.21 nmol/mg protein in controls to 1.94 +/- 0.19. Incubation of vesicles in the presence of purified catalytic subunit of cAMP-dependent protein kinase inhibited the amiloride-sensitive uptake of /sup 22/Na/sup +/ at 10. The inhibitory effect of both cAMP and catalytic subunit of cAMP-dependent protein kinase was blocked by the specific thermostable protein inhibitor of the kinase. These studies demonstrate that activation of endogenous membrane-bound cAMP-dependent protein kinase or exposure to exogenous catalytic subunit of cAMP-dependent protein kinase inhibits the rate of Na/sup +/-H/sup +/ exchange transport in the brush-border membrane of the rabbit kidney.

• Research Organization: Univ. of Texas Medical School, Houston
• OSTI ID: 6409533
• Journal Information: Am. J. Physiol.; (United States), Journal Name: Am. J. Physiol.; (United States) Vol. 252:1; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALI METAL ISOTOPES
ANIMALS
ATP
BARYONS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CHLORIDES
CHLORINE COMPOUNDS
DAYS LIVING RADIOISOTOPES
ELECTROPHORESIS
ELEMENTARY PARTICLES
ENZYMES
FERMIONS
HADRONS
HALIDES
HALOGEN COMPOUNDS
INHIBITION
ISOTOPES
KIDNEYS
LIGHT NUCLEI
MAMMALS
MEMBRANE TRANSPORT
NUCLEI
NUCLEONS
NUCLEOTIDES
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PHYSIOLOGY
PROTONS
RABBITS
RADIOISOTOPES
SODIUM 22
SODIUM CHLORIDES
SODIUM COMPOUNDS
SODIUM ISOTOPES
TRANSFERASES
UPTAKE
VERTEBRATES
YEARS LIVING RADIOISOTOPES