Inhibition by amiodarone of slow response action potentials and contraction in guinea pig ventricular muscle. 1988

M Aomine
Department of Medicine, Northwestern University Medical School, Chicago, IL 60611.

1. Effects of an antiarrhythmic agent, amiodarone (AM), on slow response action potentials and contraction of guinea pig ventricular muscle were examined. 2. AM (4.4 x 10(-5) M, 1.1 x 10(-4) M) significantly inhibited the maximum upstroke velocity of slow response action potentials and contraction. 3. As for action potential duration (APD), higher concentration (1.1 x 10(-4) M) of AM significantly shortened the APD, while low concentration (4.4 x 10(-5) M) had little effect on it. 4. These findings strongly suggest that AM blocks slow inward current inflow via Ca2+ channels in the ventricular muscle.

UI MeSH Term Description Entries
D007700 Kinetics The rate dynamics in chemical or physical systems.
D009200 Myocardial Contraction Contractile activity of the MYOCARDIUM. Heart Contractility,Inotropism, Cardiac,Cardiac Inotropism,Cardiac Inotropisms,Contractilities, Heart,Contractility, Heart,Contraction, Myocardial,Contractions, Myocardial,Heart Contractilities,Inotropisms, Cardiac,Myocardial Contractions
D002118 Calcium A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes. Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D006168 Guinea Pigs A common name used for the genus Cavia. The most common species is Cavia porcellus which is the domesticated guinea pig used for pets and biomedical research. Cavia,Cavia porcellus,Guinea Pig,Pig, Guinea,Pigs, Guinea
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
D000638 Amiodarone An antianginal and class III antiarrhythmic drug. It increases the duration of ventricular and atrial muscle action by inhibiting POTASSIUM CHANNELS and VOLTAGE-GATED SODIUM CHANNELS. There is a resulting decrease in heart rate and in vascular resistance. Amiobeta,Amiodarex,Amiodarona,Amiodarone Hydrochloride,Amiohexal,Aratac,Braxan,Corbionax,Cordarex,Cordarone,Kordaron,L-3428,Ortacrone,Rytmarone,SKF 33134-A,Tachydaron,Trangorex,Hydrochloride, Amiodarone,L 3428,L3428,SKF 33134 A,SKF 33134A
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

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