Characterization of cardiac microsomes from spontaneously hypertonic rats.
Capacity of Ca2+ sequestration was found to be significantly lowered in microsomal preparations of hearts from spontaneously hypertonic rats. A decrease to 40% of the control level was found for basal and extra ATPase. A similar reduction existed in initial and total Ca2+ uptake. These findings are correlated with a lower concentration of the Ca2+ transport ATPase in SDS gel electrophoresis, a lower density of the 7-9 nm intramembraneous particles and higher half-lives of phosphoprotein. Altered contractility of hypertrophied myocardium may thus be partially explained by the dysfunction of the Ca2+ sequestering system.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D001794:Blood Pressure; D002118:Calcium / Q000378:metabolism; D006332:Cardiomegaly / Q000503:physiopathology; D004591:Electrophoresis, Polyacrylamide Gel; D006352:Heart Ventricles / Q000033:anatomy & histology; D006973:Hypertension / Q000503:physiopathology*; D008861:Microsomes / Q000503:physiopathology* / Q000648:ultrastructure; D009206:Myocardium / Q000032:analysis*; D009929:Organ Size; D010750:Phosphoproteins / Q000096:biosynthesis; D051381:Rats; D013997:Time Factors
D010750:Phosphoproteins; D000251:Adenosine Triphosphatases; D002118:Calcium