title: Effect of prazosin treatment on the cardiac sarcolemmal ATPase in failing heart due to mitral insufficiency in dogs.
abstract: Prazosin has been used in the treatment of congestive heart failure. It is, however, not known whether prazosin gives only haemodynamic benefit or if it also produces a decrease in the cardiac sarcolemmal Na+-K+-ATPase which has been reported to be increased in the failing heart. The present investigation deals with the effect of 3 months of prazosin treatment in dogs with 3 months of induced mitral insufficiency (MI) on the sarcolemmal Na+-K+-ATPase activity. The dogs were divided into four groups each comprising of five dogs. A--normal; B--3 months of MI; C--6 months of MI; D--3 months of prazosin treatment after 3 months of MI. Three months of MI produced a decrease in the dp/dt and an increase in the end-diastolic pressure of left ventricle but no change in the index of left ventricular contractility and cardiac index. Also there was no change in the sarcolemmal Na+-K+-ATPase. There was a significant decrease in the index of left ventricular contractility and cardiac index and an increase in the LVEDP associated with a significant increase in the left ventricular sarcolemmal Na+-K+-ATPase at 6 months of MI. Sarcolemmal Mg2+-ATPase of both ventricles increased after 6 months of MI the significance of which is not known as yet. There was no change in the sarcolemmal Na+-K+-ATPase of the nonfailing right ventricle. Prazosin treatment prevented the deterioration of the left ventricular contractility and function and also prevented the increase in the sarcolemmal Na+-K+-ATPase observed in failing heart.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.forename: K
authors.initials: K
authors.lastname: Prasad
authors.forename: C L
authors.initials: CL
authors.lastname: O'Neil
authors.forename: B
authors.initials: B
authors.lastname: Bharadwaj
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism; D000818:Animals; D017301:Ca(2+) Mg(2+)-ATPase; D004285:Dogs; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D008297:Male; D008944:Mitral Valve Insufficiency / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D011224:Prazosin / Q000627:therapeutic use*; D011799:Quinazolines / Q000627:therapeutic use*; D012508:Sarcolemma / Q000201:enzymology*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
chemical_list: D011799:Quinazolines; D000251:Adenosine Triphosphatases; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase; D011224:Prazosin