Résumé
Extracellular ATP, at micromolar concentration, induces multiple functional changes in cardiac cells. Stimulation of P
2 purinoceptors is associated with Ca current increase and positive inotropic effect. On rapid application, ATP triggers membrane depolarization by activating a Cl conductance and by inducing an acidification following Cl-HCO
3 exchanger stimulation. Both effects might lead to cardiac arrhythmias following ATP release under pathophysiologic conditions.