Two forms of the Na,K-ATPase catalytic subunit detected by their immunological and electrophoretic differences. Alpha and alpha+ in mammalian heart.
Differences in the expression of Na,K-ATPase isozymes in the heart make a significant contribution to the understanding of cardiac glycoside effects in this tissue. More explicit information is needed about the cardiac glycoside affinities of the different isozymes in various species, however, before a unified picture can emerge. Much more information is also needed on what controls the level of expression of the different isozymes, and why mammalian species differ in this respect. For the rat, at least, it appears that the relative abundance of two Na,K-ATPase isozymes is controlled by changes in gene expression during development. These changes correlate with large changes in other contractile and excitable membrane properties. Isoforms of myosin and other important cardiac proteins are known to change in hypertrophy. It may be of critical importance to understand how the isoforms of the cardiac glycoside receptor change as well.
Sweadner
K J
KJ
Pappas Laboratories, Neurosurgical Service, Massachusetts General Hospital, Boston 02114.
Farshi
S K
SK
D000375:Aging; D000818:Animals; D000936:Antigen-Antibody Complex; D004586:Electrophoresis; D006321:Heart / Q000254:growth & development; D007106:Immune Sera; D007527:Isoenzymes / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D046911:Macromolecular Substances; D009206:Myocardium / Q000201:enzymology*; D051381:Rats; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D013045:Species Specificity
D000936:Antigen-Antibody Complex; D007106:Immune Sera; D007527:Isoenzymes; D046911:Macromolecular Substances; D000254:Sodium-Potassium-Exchanging ATPase