title: Effect of ICa,LBlockade on Adrenergic Stimulation in Developing Heart.
abstract: The effect of verapamil-induced blockade of L-type calcium ionic currents (ICa,L) on the action of non-selective adrenergic cardiac stimulation by norepinephrine was examined during different periods of early postnatal ontogeny. In 1-week-old rats, intravenous norepinephrine induced a short-term tachycardia both with and without preliminary injected verapamil. In 3-week-old rats, norepinephrine alone produced no chronotropic effect; in contrast, it induced a biphasic tachycardia in verapamil-treated rats. In 6- and 20-month-old rats, norepinephrine induced a short-term tachycardia, which could be prevented by verapamil. The age-related peculiarities of chronotropic action of non-selective adrenergic stimulation are indicative of the role of L-type calcium ionic channels in the development of sympathetic control over the heart.
authors: Department of Human Health Protection, Kazan (Volga Region) Federal University, Kazan, Russia. zefirovtl@mail.ru.
authors: T L
authors: TL
authors: Zefirov
authors: Department of Human Health Protection, Kazan (Volga Region) Federal University, Kazan, Russia.
authors: A M
authors: AM
authors: Kuptsova
authors: Department of Human Health Protection, Kazan (Volga Region) Federal University, Kazan, Russia.
authors: R G
authors: RG
authors: Biktemirova
authors: Department of Human Health Protection, Kazan (Volga Region) Federal University, Kazan, Russia.
authors: N I
authors: NI
authors: Ziyatdinova
authors: Department of Normal Physiology, Kazan StateMedical University, Kazan, the Republic of Tatarstan, Russia.
authors: A L
authors: AL
authors: Zefirov
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000367:Age Factors; D000375:Aging / Q000502:physiology*; D000818:Animals; D000831:Animals, Newborn; D021461:Animals, Outbred Strains; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D006321:Heart / Q000187:drug effects / Q000502:physiology; D009638:Norepinephrine / Q000494:pharmacology*; D051381:Rats; D011941:Receptors, Adrenergic / Q000378:metabolism*; D013564:Sympathetic Nervous System / Q000187:drug effects / Q000502:physiology; D013610:Tachycardia / Q000139:chemically induced / Q000378:metabolism / Q000503:physiopathology; D014700:Verapamil / Q000494:pharmacology*
chemical_list: D000316:Adrenergic alpha-Agonists; D002121:Calcium Channel Blockers; D020746:Calcium Channels, L-Type; D011941:Receptors, Adrenergic; D014700:Verapamil; D009638:Norepinephrine
keywords: L-type Ca 2+ channels; adrenoreceptors; chronotropy; heart; ontogeny