The effect of digitalis glycosides-specific antisera on the binding of the glycosides to (Na+ + K+)-ATPase.
The capability of digitalis glycoside-specific antisera to reverse the glycoside-induced inhibition of (Na+ + K+)-ATPase activity was examined. The antisera-induced reversal of the ATPase inhibition caused by digoxin was considerably slower (k-1 = 0.1177 . 10-3 .S-1) than the reversal caused by dihydrodigoxin and dihydrodigitoxin (k-1 = 4.462 . 10-3 . S-1 and K-1 = 3.609 .10-3 . S-1, respectively). In addition, the dissociation rate constants of the ouabain-induced dissociation of the various glycosides from the glycoside-ATPase complex were determined: The dissociation rate constants of the antisera-induced restoration of enzyme activity and that of the ouabain-induced dissociation of glycosides from the glycoside-enzyme complex were not significantly different.
D000818:Animals; D002417:Cattle; D004071:Digitalis Glycosides / Q000276:immunology* / Q000378:metabolism; D006801:Humans; D007106:Immune Sera; D009206:Myocardium / Q000201:enzymology; D011485:Protein Binding / Q000187:drug effects; D000254:Sodium-Potassium-Exchanging ATPase / Q000037:antagonists & inhibitors* / Q000378:metabolism; D013997:Time Factors
D004071:Digitalis Glycosides; D007106:Immune Sera; D000254:Sodium-Potassium-Exchanging ATPase