Biomaterial Database

Electrophysiologic effects of propranolol on the human heart. 1978

K Prasad, and A Kamiyama, and F Inoue

Effects of propranolol (10(-9) to 10(-4) Gm/ml) on various electrophysiologic properties of human papillary muscles obtained from patients undergoing corrective open heart surgery were studied to have an insight into the mechanism of its antiarrhythmic activity in man. Propranolol (10(-8) to 10(-6) Gm/ml) produced significant decreases in the action potential duration, effective refractory period and dv/dt of depolarization phase of action potential without significantly affecting the resting potential and amplitude of action potential. These effects were concentration dependent. High concentration (10(-4) Gm/ml) of propranolol not only produced greater decreases in the above parameters but also reduced the resting potential and amplitude of action potential. Although propranolol decreased both the action potential duration and effective refractory period, the shortening of the action potential duration was greater than the shortening of the effective refractory period. It shifted the membrane responsiveness curve to the right and down. It produced frequency dependent decreases in the dv/dt of phase 0 of action potential and the rate of repolarization. Propranolol also increased the threshold of stimulation. Propranolol produced electrophysiologic changes in the human myocardium qualitatively similar to those in canine myocardium. The probable mechanism of its antiarrhythmic activity in man has been discussed.

UI	MeSH Term	Description	Entries
D008564	Membrane Potentials	The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).	Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D008875	Middle Aged	An adult aged 45 - 64 years.	Middle Age
D010210	Papillary Muscles	Conical muscular projections from the walls of the cardiac ventricles, attached to the cusps of the atrioventricular valves by the chordae tendineae.	Muscle, Papillary,Muscles, Papillary,Papillary Muscle
D011433	Propranolol	A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.	Dexpropranolol,AY-20694,Anaprilin,Anapriline,Avlocardyl,Betadren,Dociton,Inderal,Obsidan,Obzidan,Propanolol,Propranolol Hydrochloride,Rexigen,AY 20694,AY20694,Hydrochloride, Propranolol
D012032	Refractory Period, Electrophysiological	The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.	Period, Neurologic Refractory,Periods, Neurologic Refractory,Refractory Period, Neurologic,Tetanic Fade,Vvedenskii Inhibition,Wedensky Inhibition,Inhibition, Vvedenskii,Inhibition, Wedensky,Neurologic Refractory Period,Neurologic Refractory Periods,Neuromuscular Fade,Neuromuscular Transmission Fade,Refractory Period, Neurological,Refractory Periods, Neurologic,Electrophysiological Refractory Period,Electrophysiological Refractory Periods,Fade, Neuromuscular,Fade, Neuromuscular Transmission,Fade, Tetanic,Neurological Refractory Period,Neurological Refractory Periods,Refractory Periods, Electrophysiological,Refractory Periods, Neurological,Transmission Fade, Neuromuscular
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
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
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In