Age-related peculiarities of adrenergic regulation of cardiac chronotropic action after I f blockage

The effects of norepinephrine on the heart rate were studied in 1-, 3-, 6-, and 20-week-old rats before and after blockade of hyperpolarization-activated currents (I f , I h ). In animals with mature sympathetic regulation of cardiac activity (6- and 20-week-old animals), I f blockage decreased the...

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Bibliographic Details
Published in:Bulletin of experimental biology and medicine 2013-11, Vol.156 (1), p.1-3
Main Authors: Ziyatdinova, N I, Dement'eva, R E, Khisamieva, L I, Zefirov, T L
Format: Article
Language:English
Subjects:
Adrenergic alpha-Agonists - pharmacology
Age Factors
Aging
Animals
Cardiotonic Agents - pharmacology
Heart Rate - drug effects
Norepinephrine - pharmacology
Pyrimidines - pharmacology
Rats
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Summary:The effects of norepinephrine on the heart rate were studied in 1-, 3-, 6-, and 20-week-old rats before and after blockade of hyperpolarization-activated currents (I f , I h ). In animals with mature sympathetic regulation of cardiac activity (6- and 20-week-old animals), I f blockage decreased the severity of norepinephrine-induced tachycardia. In newborn rats lacking sympathetic innervation of the heart, norepinephrine only slightly affected heart rate before and after I f blockage. In 3-week-old animals, I f blockage after norepinephrine pretreatment increased tachycardia.
ISSN:1573-8221