Ouabain binding sites and (Na/sup +/,K/sup +/)-ATPase activity in rat cardiac hypertrophy: expression of the neonatal forms

Journal Article · Sun Jan 05 04:00:00 EST 1986 · J. Biol. Chem.; (United States)

OSTI ID:5180168

The adaptation of the myocardium to mechanical overload which results in cardiac hypertrophy involved several membrane functions. The digitalis receptor in sarcolemma vesicles from hypertrophied rat hearts is characterized by binding of (/sup 3/H)ouabain and ouabain-induced inhibition of (Na/sup +/,K/sup +/)-ATPase. The results show the existence of two families of ouabain binding sites with apparent dissociation constants (K/sub d/) of 1.8-3.2 x 10/sup -8/ M and 1-8 x 10/sup -6/ M, respectively, which are similar to those found in normal hearts. The presence of the high affinity receptor in hypertrophied rat heart is correlated to a detectable inhibition of the (Na/sup +/,K/sup +/)-ATPase (IC/sub 50/ = 1-3 x 10/sup -8/ M). However, the high and low affinity sites in hypertrophied hearts bind and release ouabain at 4-5-fold slower rates than the corresponding sites in normal hearts. These properties are similar to that observed in newborn rat cardiac preparations. Taken together with the expression of myosin isoforms, the data show that the physiological adaptation of the heart also involves the resurgence of the neonatal forms of the digitalis receptor.

• Research Organization: Universite Paris, France
• OSTI ID: 5180168
• Journal Information: J. Biol. Chem.; (United States), Journal Name: J. Biol. Chem.; (United States) Vol. 261:1; ISSN JBCHA
• Country of Publication: United States
• Language: English

Related Subjects

550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ALKALI METAL COMPOUNDS
ANIMALS
ATP-ASE
BIOCHEMICAL REACTION KINETICS
BIOLOGICAL ADAPTATION
BODY
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CATIONS
CHARGED PARTICLES
DATA
DIGITALIS
DRUGS
ENZYME INHIBITORS
ENZYMES
EXPERIMENTAL DATA
GLOBULINS
GLYCOSIDES
HEART
HYDROLASES
HYPERTROPHY
INFORMATION
INHIBITION
IONS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
MAMMALS
MEDICINAL PLANTS
MEMBRANE PROTEINS
MYOSIN
NEONATES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANS
OUABAIN
PATHOLOGICAL CHANGES
PHOSPHOHYDROLASES
PLANTS
POTASSIUM COMPOUNDS
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SODIUM COMPOUNDS
STROPHANTHINS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES