Angiotensin II-induced increase of T-type Ca2+ current and decrease of L-type Ca2+ current in heart cells.
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.
Bkaily
Ghassan
G
Department of Anatomy & Cell Biology, Faculty of Medicine, Université de Sherbrooke, 3001-12th Avenue North, Sherbrooke, Que., Canada J1H 5N4. Ghassan.Bkaily@USherbrooke.ca
Sculptoreanu
Adrian
A
Wang
Shimin
S
Nader
Moni
M
Hazzouri
Khaled M
KM
Jacques
Danielle
D
Regoli
Domenico
D
D'Orleans-Juste
Pedro
P
Avedanian
Levon
L
D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D020746:Calcium Channels, L-Type / Q000187:drug effects* / Q000502:physiology; D020747:Calcium Channels, T-Type / Q000187:drug effects* / Q000502:physiology; D002642:Chick Embryo; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods; D006352:Heart Ventricles / Q000187:drug effects* / Q000196:embryology; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008301:Maleimides / Q000494:pharmacology; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000187:drug effects / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D016276:Ventricular Function
D020746:Calcium Channels, L-Type; D020747:Calcium Channels, T-Type; D007211:Indoles; D008301:Maleimides; D000804:Angiotensin II; D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; C088060:bisindolylmaleimide; D002118:Calcium