Effects of hypokalemia on the cardiotropic actions of digoxin in dogs. Correlation with inhibition of cardiac Na+,K+-adenosine triphosphatase.
Hypokalemia potentiated the arryhthmogenic effects of digoxin and promoted inhibition of cardiac Na+,K+-ATPase. Acute hypokalemia did not modify digoxin-induced inotropy and therefore altered the quantitative relationship between inhibition of Na+,K+-ATPase and positive inotropy. Chronic hypokalemia impaired the positive inotropic response to digoxin and to isoproterenol in the absence of an electron microscopically detectable cardiomyopathy.
D000208:Acute Disease; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors; D000818:Animals; D002908:Chronic Disease; D004077:Digoxin / Q000008:administration & dosage / Q000494:pharmacology*; D004285:Dogs; D007008:Hypokalemia / Q000503:physiopathology*; D007545:Isoproterenol / Q000494:pharmacology; D009200:Myocardial Contraction / Q000187:drug effects*; D011188:Potassium / Q000037:antagonists & inhibitors; D012964:Sodium / Q000037:antagonists & inhibitors*
D004077:Digoxin; D012964:Sodium; D000251:Adenosine Triphosphatases; D007545:Isoproterenol; D011188:Potassium