Biomaterial Database

Effect of ouabain in catecholamine-induced cardiac hypertrophy. 1995

J Mészáros, and B Pásztor

Department of Comparative Animal Physiology, Kossuth University, Debrecen, Hungary.

Changes in the sensitivity to ouabain of the hypertrophied myocardium were studied in isolated left ventricular trabeculae of rat heart using conventional microelectrode technique, and in anaesthetized rats using limb-lead electrocardiography (ECG). Hypertrophy was induced by administration of 5 mg/kg isoprenaline once daily for 7 days. The age-matched normal control rats received the same volume of 0.9% NaCl solution. The heart weight to body weight ratio increased from 3.23 +/- 0.07 mg/kg to 4.37 +/- 0.12 mg/kg, which means a 35% hypertrophy. The action potential duration at 50% repolarization (APD50) was 25.1 +/- 2.4 ms in normal case and 63.5 +/- 4.6 ms in hypertrophy. The S-T interval of the ECG was 24.9 +/- 1.9 ms in normal rats and 64.4 +/- 3.4 ms in hypertrophy. The toxic effect of ouabain was studied by determining the concentrations of the drug at which arrhythmogenic transient depolarizations (TDs; in microelectrode experiments) or sustained ventricular tachyarrhythmias (VTAs; in ECG experiments) appeared. The dose of ouabain inducing TDs was 345 +/- 25 microM in normal case and 630 +/- 40 microM in hypertrophy. In ECG studies, the dose inducing VTAs was 19.1 +/- 3.6 mg/kg in normal rats and 34.3 +/- 3.1 mg/kg in hypertrophy. The results suggest that catecholamine-induced cardiac hypertrophy damages the membrane-bound Na+, K(+)-ATPase, thus decreasing the number of the ouabain binding sites, which consequently, makes the myocardium membrane more insensitive to ouabain.

UI	MeSH Term	Description	Entries
D007545	Isoproterenol	Isopropyl analog of EPINEPHRINE; beta-sympathomimetic that acts on the heart, bronchi, skeletal muscle, alimentary tract, etc. It is used mainly as bronchodilator and heart stimulant.	Isoprenaline,Isopropylarterenol,4-(1-Hydroxy-2-((1-methylethyl)amino)ethyl)-1,2-benzenediol,Euspiran,Isadrin,Isadrine,Isopropyl Noradrenaline,Isopropylnoradrenaline,Isopropylnorepinephrine,Isoproterenol Hydrochloride,Isoproterenol Sulfate,Isuprel,Izadrin,Norisodrine,Novodrin,Hydrochloride, Isoproterenol,Noradrenaline, Isopropyl,Sulfate, Isoproterenol
D008297	Male		Males
D009206	Myocardium	The muscle tissue of the HEART. It is composed of striated, involuntary muscle cells (MYOCYTES, CARDIAC) connected to form the contractile pump to generate blood flow.	Muscle, Cardiac,Muscle, Heart,Cardiac Muscle,Myocardia,Cardiac Muscles,Heart Muscle,Heart Muscles,Muscles, Cardiac,Muscles, Heart
D010042	Ouabain	A cardioactive glycoside consisting of rhamnose and ouabagenin, obtained from the seeds of Strophanthus gratus and other plants of the Apocynaceae; used like DIGITALIS. It is commonly used in cell biological studies as an inhibitor of the NA(+)-K(+)-EXCHANGING ATPASE.	Acocantherin,G-Strophanthin,Acolongifloroside K,G Strophanthin
D004562	Electrocardiography	Recording of the moment-to-moment electromotive forces of the HEART as projected onto various sites on the body's surface, delineated as a scalar function of time. The recording is monitored by a tracing on slow moving chart paper or by observing it on a cardioscope, which is a CATHODE RAY TUBE DISPLAY.	12-Lead ECG,12-Lead EKG,12-Lead Electrocardiography,Cardiography,ECG,EKG,Electrocardiogram,Electrocardiograph,12 Lead ECG,12 Lead EKG,12 Lead Electrocardiography,12-Lead ECGs,12-Lead EKGs,12-Lead Electrocardiographies,Cardiographies,ECG, 12-Lead,EKG, 12-Lead,Electrocardiograms,Electrocardiographies, 12-Lead,Electrocardiographs,Electrocardiography, 12-Lead
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D006332	Cardiomegaly	Enlargement of the HEART, usually indicated by a cardiothoracic ratio above 0.50. Heart enlargement may involve the right, the left, or both HEART VENTRICLES or HEART ATRIA. Cardiomegaly is a nonspecific symptom seen in patients with chronic systolic heart failure (HEART FAILURE) or several forms of CARDIOMYOPATHIES.	Cardiac Hypertrophy,Enlarged Heart,Heart Hypertrophy,Heart Enlargement,Cardiac Hypertrophies,Enlargement, Heart,Heart Hypertrophies,Heart, Enlarged,Hypertrophies, Cardiac,Hypertrophies, Heart,Hypertrophy, Cardiac,Hypertrophy, Heart
D000200	Action Potentials	Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli.	Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000254	Sodium-Potassium-Exchanging ATPase	An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.	ATPase, Sodium, Potassium,Adenosinetriphosphatase, Sodium, Potassium,Na(+)-K(+)-Exchanging ATPase,Na(+)-K(+)-Transporting ATPase,Potassium Pump,Sodium Pump,Sodium, Potassium ATPase,Sodium, Potassium Adenosinetriphosphatase,Sodium-Potassium Pump,Adenosine Triphosphatase, Sodium, Potassium,Na(+) K(+)-Transporting ATPase,Sodium, Potassium Adenosine Triphosphatase,ATPase Sodium, Potassium,ATPase, Sodium-Potassium-Exchanging,Adenosinetriphosphatase Sodium, Potassium,Pump, Potassium,Pump, Sodium,Pump, Sodium-Potassium,Sodium Potassium Exchanging ATPase,Sodium Potassium Pump