Quantitative determination of Na sup + -K sup + -ATPase and other sarcolemmal components in muscle cells

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

OSTI ID:7027174

Hansen, O; Clausen, T ^[1]

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1. Aarhus Univ. (Denmark)

A recurring problem in the characterization of plasma membrane enzymes in tissues and cells is whether the samples tested are representative for the entire population of enzyme molecules present in the starting material. Measurements of ({sup 3}H)-ouabain binding, enzyme activity, and maximum transport capacity all indicate that the concentration of Na{sup +}-K{sup +} pumps in mammalian skeletal muscle is high. Studies on Na{sup +}-K{sup +}-ATPase activity in isolated sarcolemma, however, generally give little or no information on total cellular enzyme concentration. Due to the low and variable enzyme recovery, such subcellular preparations may, therefore, give misleading data on factors regulating Na{sup +}-K{sup +}-ATPase in heart and skeletal muscle cells. As the same isolation and purification procedures are used for the study of other sarcolemmal components, this inadequate recovery has general implications for statements on regulatory changes in the sarcolemmal composition of muscle cells. On the other hand, complete quantification of Na{sup +}-K{sup +}-ATPase in muscle tissue can now be achieved using simple procedures and the entire material. Recent studies have shown that regulatory changes in the entire population of Na{sup +}-K{sup +} pumps in muscle can be quantified in measurements of ({sup 3}H)-ouabain binding, K{sup +}-activated 3-O-methylfluorescein phosphatase activity, as well as maximum ouabain suppressible Na{sup +}-K{sup +} transport capacity.

• OSTI ID: 7027174
• Journal Information: American Journal of Physiology; (USA), Journal Name: American Journal of Physiology; (USA) Vol. 254:1; ISSN 0002-9513; ISSN AJPHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACID ANHYDRASES
ALKALI METAL COMPOUNDS
ANIMAL CELLS
ATP-ASE
BIOCHEMISTRY
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CATIONS
CHARGED PARTICLES
CHEMICAL REACTIONS
CHEMISTRY
CROSS-LINKING
DRUGS
ENZYME ACTIVITY
ENZYMES
GLYCOSIDES
HYDROGEN COMPOUNDS
HYDROLASES
IONS
MUSCLES
ORGANIC COMPOUNDS
OUABAIN
PHOSPHOHYDROLASES
POLYMERIZATION
POTASSIUM COMPOUNDS
SODIUM COMPOUNDS
STROPHANTHINS
TRITIUM COMPOUNDS