Sarcolemmal ATPase activities of the rat heart ventricle--dependence on age and sodium ion.
Na-K-ATPase activity of the rat heart was similar throughout the postnatal growth when measured from crude unpurified fraction. Instead in the cardiac sarcolemmal fraction, isolated by hypotonic shock LiBr-treatment method, the activity was over two times higher in 10-day old neonates than in adult rats. The conflicting results are partly explained by different effects of the isolation procedure on neonatal and adult tissues. Na concentration for half-maximal activity of the Na-K-ATPase was similar in neonates (7.0 mM) and adults (6.4 mM). Ca-ATPase activity was not affected by Na concentration (2-100 mM) in the two age-groups studied.
D000375:Aging; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D005260:Female; D006321:Heart / Q000254:growth & development*; D006352:Heart Ventricles / Q000201:enzymology / Q000254:growth & development; D008297:Male; D009206:Myocardium / Q000201:enzymology*; D051381:Rats; D011919:Rats, Inbred Strains; D012508:Sarcolemma / Q000201:enzymology* / Q000648:ultrastructure; D012964:Sodium / Q000494:pharmacology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D012964:Sodium; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase