Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies

The effects of a wide range of Prostacyclin (PGI2) concentrations on the Isometric Developed Tension (IDT) of isolated left auricles driven at different frequencies (0.8, 1.6 or 3.3 Hz) were explored. A comparison of the positive inotropism of PGI2, norepinephrine (NE), tyramine and phenylephrine (P...

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Detalles Bibliográficos
Publicado: 1980
Materias:
Catecholamines
Inotropic Effect
Myocarium
PGI2
Rate of Contraction
3',4' dihydroxy 2 methylpropiophenone
cocaine
noradrenalin
normetadrenalin
oxidopamine
phenylephrine
propranolol
prostacyclin
tyramine
animal experiment
controlled study
drug comparison
drug response
heart
heart atrium
heart muscle contractility
heart rate
in vitro study
inotropism
rat
Animals
Cocaine
Epoprostenol
Heart Rate
Male
Myocardial Contraction
Norepinephrine
Phenylephrine
Propranolol
Prostaglandins
Rats
Stimulation, Chemical
Sympathetic Nervous System
Tyramine
Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00281298_v313_n2_p95_SterinBorda
http://hdl.handle.net/20.500.12110/paper_00281298_v313_n2_p95_SterinBorda
Aporte de:
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires
id paper:paper_00281298_v313_n2_p95_SterinBorda
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spelling paper:paper_00281298_v313_n2_p95_SterinBorda2023-06-08T14:54:52Z Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies Catecholamines Inotropic Effect Myocarium PGI2 Rate of Contraction 3',4' dihydroxy 2 methylpropiophenone cocaine noradrenalin normetadrenalin oxidopamine phenylephrine propranolol prostacyclin tyramine animal experiment controlled study drug comparison drug response heart heart atrium heart muscle contractility heart rate in vitro study inotropism rat Animals Cocaine Epoprostenol Heart Rate Male Myocardial Contraction Norepinephrine Phenylephrine Propranolol Prostaglandins Rats Stimulation, Chemical Sympathetic Nervous System Tyramine The effects of a wide range of Prostacyclin (PGI2) concentrations on the Isometric Developed Tension (IDT) of isolated left auricles driven at different frequencies (0.8, 1.6 or 3.3 Hz) were explored. A comparison of the positive inotropism of PGI2, norepinephrine (NE), tyramine and phenylephrine (Phenyl) indicated that PGI2, NE and tyramine enhanced peak tension significantly less at slow (0.8 and 1.6 Hz) than at higher rates (3.3 Hz); whereas Phenyl augmented equally the IDT at all of these three driving frequencies. The positive inotropism evoked by PGI2 was inhibited by (-)-propranolol and also by a treatment with 6-OHDA. Cocaine, normetanephrine and U-0521, augmented the positive inotropic influence of PGI2 on atria paced at a slow rate (0.8 Hz) but not at a faster one (3.3 Hz). These results suggest that the action of PGI2 on atrial contractions is apparently indirect and mediated by the release of tissue catecholamines. In addition the effect of PGI2 and NE at slow and fast rates appears associated with a different relative relevance of the processes which terminate the action of added sympathomimetic agonists, namely, neuronal or extraneuronal uptake as well as metabolization via COMT. These mechanisms seen to be more prominent at slower driving frequencies and could explain the diminished effect of PGI2 and NE on slowly paced atria. © 1980 Springer-Verlag. 1980 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00281298_v313_n2_p95_SterinBorda http://hdl.handle.net/20.500.12110/paper_00281298_v313_n2_p95_SterinBorda
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Catecholamines
Inotropic Effect
Myocarium
PGI2
Rate of Contraction
3',4' dihydroxy 2 methylpropiophenone
cocaine
noradrenalin
normetadrenalin
oxidopamine
phenylephrine
propranolol
prostacyclin
tyramine
animal experiment
controlled study
drug comparison
drug response
heart
heart atrium
heart muscle contractility
heart rate
in vitro study
inotropism
rat
Animals
Cocaine
Epoprostenol
Heart Rate
Male
Myocardial Contraction
Norepinephrine
Phenylephrine
Propranolol
Prostaglandins
Rats
Stimulation, Chemical
Sympathetic Nervous System
Tyramine
spellingShingle Catecholamines
Inotropic Effect
Myocarium
PGI2
Rate of Contraction
3',4' dihydroxy 2 methylpropiophenone
cocaine
noradrenalin
normetadrenalin
oxidopamine
phenylephrine
propranolol
prostacyclin
tyramine
animal experiment
controlled study
drug comparison
drug response
heart
heart atrium
heart muscle contractility
heart rate
in vitro study
inotropism
rat
Animals
Cocaine
Epoprostenol
Heart Rate
Male
Myocardial Contraction
Norepinephrine
Phenylephrine
Propranolol
Prostaglandins
Rats
Stimulation, Chemical
Sympathetic Nervous System
Tyramine
Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies
topic_facet Catecholamines
Inotropic Effect
Myocarium
PGI2
Rate of Contraction
3',4' dihydroxy 2 methylpropiophenone
cocaine
noradrenalin
normetadrenalin
oxidopamine
phenylephrine
propranolol
prostacyclin
tyramine
animal experiment
controlled study
drug comparison
drug response
heart
heart atrium
heart muscle contractility
heart rate
in vitro study
inotropism
rat
Animals
Cocaine
Epoprostenol
Heart Rate
Male
Myocardial Contraction
Norepinephrine
Phenylephrine
Propranolol
Prostaglandins
Rats
Stimulation, Chemical
Sympathetic Nervous System
Tyramine
description The effects of a wide range of Prostacyclin (PGI2) concentrations on the Isometric Developed Tension (IDT) of isolated left auricles driven at different frequencies (0.8, 1.6 or 3.3 Hz) were explored. A comparison of the positive inotropism of PGI2, norepinephrine (NE), tyramine and phenylephrine (Phenyl) indicated that PGI2, NE and tyramine enhanced peak tension significantly less at slow (0.8 and 1.6 Hz) than at higher rates (3.3 Hz); whereas Phenyl augmented equally the IDT at all of these three driving frequencies. The positive inotropism evoked by PGI2 was inhibited by (-)-propranolol and also by a treatment with 6-OHDA. Cocaine, normetanephrine and U-0521, augmented the positive inotropic influence of PGI2 on atria paced at a slow rate (0.8 Hz) but not at a faster one (3.3 Hz). These results suggest that the action of PGI2 on atrial contractions is apparently indirect and mediated by the release of tissue catecholamines. In addition the effect of PGI2 and NE at slow and fast rates appears associated with a different relative relevance of the processes which terminate the action of added sympathomimetic agonists, namely, neuronal or extraneuronal uptake as well as metabolization via COMT. These mechanisms seen to be more prominent at slower driving frequencies and could explain the diminished effect of PGI2 and NE on slowly paced atria. © 1980 Springer-Verlag.
title Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies
title_short Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies
title_full Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies
title_fullStr Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies
title_full_unstemmed Inotropic effect of prostacyclin (PGI2) on isolated rat atria at different contraction frequencies
title_sort inotropic effect of prostacyclin (pgi2) on isolated rat atria at different contraction frequencies
publishDate 1980
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00281298_v313_n2_p95_SterinBorda
http://hdl.handle.net/20.500.12110/paper_00281298_v313_n2_p95_SterinBorda
_version_ 1768545250146516992

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