Modification of K+ channel properties induced by fatty acids in neuroblastoma cells.

The effects of fatty acids on voltage-dependent potassium (K+) channels in neuroblastoma cells were studied using the whole-cell current recording technique. At a concentration of 5 microM, unsaturated and medium chain length (C10-C14) saturated fatty acids accelerated the apparent inactivation of the K+ current. This effect was reversed by albumin. In the absence of exogenous fatty acids, albumin slowed the inactivation of the K+ current. The acceleration of the K+ current inactivation induced by unsaturated fatty acids was associated with an increase in the sensitivity of K+ channels to 4-amino-pyridine. It is concluded that kinetic and pharmacological properties of K+ channels are, in part, controlled by membrane fatty acids which, in this way, should contribute to an apparent diversity of K+ channels and the modulation of cell excitability.