Atrial and ventricular myosin during development and senescence of the rat.
Myosin was isolated from rat atrial and ventricular myocardium and examined during post-natal development and senescence. The post-natal increase of Ca2+-ATPase activity of myosin from rat atria did not run in parallel with changes of ATPase activity of myosin from the ventricles. Ca2+-ATPase of both atrial and ventricular myosin was activated at pH 9.5, when compared with the assay performed at pH 7.5. The myosin light-chain subunits in the ventricles were different from the light-chain subunits in the atria, when characterized by SDS-polyacrylamide gel electrophoresis and the pattern remained practically unchanged during development, with the exception of atrial myosin from new-born and very old rats which contained an additional protein of low molecular weight.
D000375:Aging; D000818:Animals; D000831:Animals, Newborn; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D006321:Heart / Q000254:growth & development*; D006325:Heart Atria / Q000254:growth & development; D006352:Heart Ventricles / Q000254:growth & development; D009206:Myocardium / Q000201:enzymology; D009218:Myosins / Q000378:metabolism*; D051381:Rats
D009218:Myosins; D000252:Calcium-Transporting ATPases