The stretch-activated ion channel blocker gadolinium also blocks L-type calcium channels in isolated ventricular myocytes of the guinea-pig.
We show that gadolinium (Gd3+) is a potent calcium channel blocker in guinea-pig isolated ventricular myocytes. A dose-dependent inhibition of ICaL was found with an EC50 of 1.4 microM and a complete inhibition at 10 microM Gd3+. When compared with Cd2+, it appeared that the blockade of ICaL is a complex phenomenon probably involving more than one site of interaction (a Hill coefficient of 1.6 was found for Gd3+ vs. 1.0 for Cd2+). It is concluded that Gd3+ ions completely block ICaL at concentrations used to block stretch-activated channels (SAC), rendering its use as a specific SAC inhibitor problematic.
Lacampagne
A
A
Laboratoire de Physiologie des Cellules Cardiaques et Vasculaires, EP21 CNRS, Faculté des Sciences, Tours, France.
Gannier
F
F
Argibay
J
J
Garnier
D
D
Le Guennec
J Y
JY
D000818:Animals; D001696:Biomechanical Phenomena; D002104:Cadmium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D005682:Gadolinium / Q000494:pharmacology*; D006168:Guinea Pigs; D006352:Heart Ventricles / Q000166:cytology / Q000187:drug effects*; D066298:In Vitro Techniques; D008564:Membrane Potentials; D016276:Ventricular Function
D002121:Calcium Channel Blockers; D002104:Cadmium; D005682:Gadolinium