title: [Effect of simulated gravitational loading on chick embryo myocardium].
abstract: Daily centrifugation of 5--8-day embryos at 7 G for 20 min by means of a specially designed attachment to dlHP-1 decreased the amplitude and increased the rate of rhythmic activity of ventricular myocytes, the automatic activity of atrial pacemakers remaining unaltered. These changes were accompanied by a decrease of Ca2+-sensitivity of myocytes. Daily centrifugation of 11--20-day chick embryos led to myocardial hypertrophy and increase in the diameter of myocardiocytes as well as to decrease in the content of actin, troponin-T and the second light chain of myosin, increase in the content of tropomyosin and emergence of the third light chain of myosin in the electrophoregrams. It appears that the changes in the composition of protein subunits of the contractile system are induced by selective activation of proteolytic enzymes in the muscle tissue.
mesh_terms: D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002642:Chick Embryo; D006112:Gravitation; D006321:Heart / Q000196:embryology*; D006329:Heart Conduction System / Q000196:embryology; D009124:Muscle Proteins / Q000032:analysis; D009200:Myocardial Contraction / Q000187:drug effects; D009206:Myocardium / Q000032:analysis / Q000166:cytology
chemical_list: D009124:Muscle Proteins; D002118:Calcium
vernacular_title: Vliianie na miokard kurinogo émbriona modelirovannoĭ gravitatsionnoĭ peregruzki.