title: Proteinous amino acids in hearts' muscle cytosol of rats pretreated with digoxin, caffeine or isoproterenol.
abstract: Levels of the 19 proteinous amino acids and total free amino acids were assayed by gas-liquid chromatography in cytosols of rat atrial and ventricular muscle cardiomyocytes. The tissues were assayed after the rats had been exposed to the cardioactive drugs digoxin, caffeine, and isoproterenol, each having different mechanisms of action. We demonstrated that, in the atrial and ventricular cardiac muscle cytosol of control (untreated) rats, arginine, glutamine, and cysteine existed in their highest levels: 35.1% and 17.6%; 14.8% and 51.6%; 9.9% and 0.25% of the total free amino acids, respectively. The levels of the other amino acids in the atrial and ventricular cardiac muscle cytosols ranged between 0.1% and 10.0% of the total free amino acids. Digoxin, caffeine, and isoproterenol significantly reduced the total amount of cytosolic free amino acids in the atrial heart muscle cytosol to 7.6%, 9.0%, and 9.2% of the control value (100%), and in the ventricular heart muscle cytosol to 31.1%, 43.2%, and 28.3% of the control. The three drugs tested changed the cytosols' levels of arginine, cysteine, tryptophane, asparagine, and tyrosine in atrial and ventricular heart muscle cytosol, as compared to the control groups (calculated as a percent of the total free amino acids in the experimental groups). The role of proteinous amino acids in the function of the heart muscle and in the mechanism of action of these drugs on the mammalian heart is discussed.
authors.affiliation: Department of Histology and Embryology, Medical University of Silesia, Zabrze, Poland.
authors.forename: Janusz
authors.initials: J
authors.lastname: Gabrys
authors.forename: Janusz
authors.initials: J
authors.lastname: Konecki
authors.forename: Maria
authors.initials: M
authors.lastname: Głowacka
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Durczok
authors.forename: Przemysław
authors.initials: P
authors.lastname: Nowak
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Bielaczyc
authors.forename: Ryszard
authors.initials: R
authors.lastname: Brus
authors.forename: Jashovam
authors.initials: J
authors.lastname: Shani
mesh_terms: D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D003600:Cytosol / Q000378:metabolism; D004077:Digoxin / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects / Q000378:metabolism; D006352:Heart Ventricles / Q000187:drug effects / Q000378:metabolism; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D000596:Amino Acids; D002110:Caffeine; D004077:Digoxin; D007545:Isoproterenol