Effect of Calcium-Activated Chloride Current Blockade on the Delayed Afterdepolarizations. Simulation Study.

摘要

High intracellular calcium conditions cause a calcium-activated transient inward current (I to the ti) that can provoke oscillations in membrane potential called delayed afterdepolarizations (DAD). The current I to the ti comprises of the sodium-calcium exchange current (I to the CI-Ca) and the calcium activated chloride current (1ci-ca) Lindblad, Murphey, Clark and Ciles developed a mathematical model (LMCC model) of the rabbit atrial AP, In this study, a modified AP LMCC model that includes I to the ci-ca is used to evaluate the contribution of I to the ci-ca to develope DADs, Our results suggest that although I to the NaCa is the main component of I to the ti (65% ), I to the ci-ca may play a significant role in DAD generation, Even more, the I to the ci- ca blockade could inhibit the DAD propagation and trigger activity associated to high Ca2+ condition, in atrial tissue.