title: Human atrial and ventricular myosin light-chains subunits in the adult and during development.
abstract: 1. Myosin was isolated from human right- and left-atrial and -ventricular myocardium, and examined both in adult subjects and at different stages during pre- and post-natal development. 2. The myosin light-chain subunits in the atria and ventricles were different when characterized by isoelectric focusing and subsequent two-dimensional poly-acrylamide-gel electrophoresis. 3. No differences were observed between the light-chain subunits in the right and left ventricle at any stage of development. 4. The foetal ventricle contained a characteristic light chain that was a major component throughout the latter half of gestation. This foetal light chain, which disappeared in the postnatal period, could not be distinguished from adult atrial light chain 1 on two-dimensional electrophoresis. 5. Myosin in the adult atria, particularly the left, contained components similar to ventricular light-chain components. 6. The possible stimuli for the observed changes in myosin light-chain expression are discussed in relation to the known physiological changes occurring during development.
mesh_terms: D000328:Adult; D000368:Aged; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005318:Fetal Heart / Q000378:metabolism; D006321:Heart / Q000254:growth & development; D006325:Heart Atria / Q000378:metabolism; D006352:Heart Ventricles / Q000378:metabolism; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007525:Isoelectric Focusing; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism*; D009218:Myosins / Q000378:metabolism*
chemical_list: D009218:Myosins