[ATPase activity and binding of calcium by sarcoplasmic reticulum of the myocardium in coronary insufficiency].
After local restriction by 70% and 90% of coronary circulation the properties of calcium pump were altered in myocardial sarcoplasmic reticulum (SR), since the activity of Ca2+-dependent ATPase and binding of 45Ca2+ by the SR membranes in the ischemic zone and out of it were decreased. Increase in the ischemic state made these alterations more distinct. Under conditions of the experiment content of ATP decreased and the metabolism of electrolytes was altered. A decrease in potassium and an increase in intracellular sodium content as well as a marked decrease in the ratio Ki/Ke were noted. Content of Ca2+ was simultaneously increased 2-2.5-fold in myocardium. These alterations might be responsible for impairment of normal ratios of systole/diastole cycles as well as for a decrease in the contractile functions of myocardium in ischemia.
D000818:Animals; D001693:Biological Transport, Active; D001794:Blood Pressure; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D003327:Coronary Disease / Q000201:enzymology* / Q000503:physiopathology; D004285:Dogs; D004573:Electrolytes / Q000378:metabolism; D007700:Kinetics; D009206:Myocardium / Q000201:enzymology*; D011188:Potassium / Q000378:metabolism; D012519:Sarcoplasmic Reticulum / Q000201:enzymology*; D012964:Sodium / Q000378:metabolism
D004573:Electrolytes; D012964:Sodium; D000252:Calcium-Transporting ATPases; D011188:Potassium; D002118:Calcium
ATF-aznaia aktivnost' i sviazyvanie kal'tsiia sarkoplazmaticheskim retikulumom miokarda pri koronarnoĭ nedostatochnosti.