HORMONAL-REGULATION OF CARDIAC CYSTIC-FIBROSIS TRANSMEMBRANE CONDUCTANCE REGULATOR CHLORIDE CHANNELS

The chloride conductance that arises from the stimulation of beta-adre noceptors has been shown to be carried by a cardiac isoform of cystic fibrosis transmembrane conductance regulator (CFTR) Cl- channels. This brief review will focus first upon the cellular signal transduction s ystem for the activation of this type of Cl- channels and then its reg ulation by catecholamines, muscarinic agonists, endothelin-1 and angio tensin-II. Both in physiological and pathological conditions, the comp lex interaction of these agonists modulates the Cl- conductance, which is potentially arrhythmogenic by shortening the action potential dura tion and inducing the depolarization.