Differential regulation of voltage-activated potassium currents in cultured human atrial myocytes

The behavior of voltage-activated outward K+ current components was analyzed during the serum-stimulated growth of cultured human atrial myocytes. The density of the rapidly inactivating component (Ito,1) of the K+ current decreased more rapidly than the density of the slowly inactivating component in chronically overloaded atrial myocytes. A decrease in the rate of inactivation and recovery from inactivation of Ito,1 was also detected during the serum-induced growth of human atrial myocytes.