Abstract
The effect of angiotensin II (Ang II) on the T- and L-type calcium currents (I(Ca)) in single ventricular heart cells of 18-week-old fetal human and 10-day-old chick embryos was studied using the whole-cell voltage clamp technique. Our results showed that in both, human and chick cardiomyocytes, Ang II (10(-7)M) increased the T-type calcium current and decreased the L-type I(Ca). The effect of Ang II on both types of currents was blocked by the AT1 peptidic antagonist, [Sar1, Ala8] Ang II (2 x 10(-7)M). Protein kinase C activator, phorbol 12,13-dibutyrate, mimicked the effect of Ang II on the T- and L-type calcium currents. These results demonstrate that in fetal human and chick embryo cardiomyocytes Ang II affects the T- and L-type Ca2+ currents differently, and this effect seems to be mediated by the PKC pathway.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Angiotensin II / pharmacology*
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Animals
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Calcium / metabolism*
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Calcium Channels, L-Type / drug effects*
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Calcium Channels, L-Type / physiology
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Calcium Channels, T-Type / drug effects*
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Calcium Channels, T-Type / physiology
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Chick Embryo
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Dose-Response Relationship, Drug
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Electrophysiology / instrumentation
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Electrophysiology / methods
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Heart Ventricles / drug effects*
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Heart Ventricles / embryology
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Humans
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Indoles / pharmacology
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Maleimides / pharmacology
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Myocytes, Cardiac / cytology
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Myocytes, Cardiac / drug effects*
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Myocytes, Cardiac / physiology
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Phorbol 12,13-Dibutyrate / pharmacology
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Protein Kinase C / drug effects
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Protein Kinase C / metabolism
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Signal Transduction / drug effects
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Signal Transduction / physiology
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Time Factors
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Ventricular Function
Substances
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Calcium Channels, L-Type
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Calcium Channels, T-Type
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Indoles
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Maleimides
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Angiotensin II
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Phorbol 12,13-Dibutyrate
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Protein Kinase C
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bisindolylmaleimide
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Calcium