[Effect of homologous n-alkanoic acids on the function of isolated skeletal muscles. IV. Effect of Na-octanoate on action potentials].

Na-octanoate decreases the amplitude, the rate of rise, and the rate of repolarization of the action potential of isolated frog skeletal muscle fibres. The threshold for excitation is increased but the conduction velocity of the action potential is decreased by octanoate. The effects depend on both the concentration of the fatty acid (0.5-8 mM) and the time of exposure (5-20 min). It is suggested that octanoate alters the conductance changes associated with a membrane action potential. The possible role of an octanoate-induced decrease in Cl(-)-permeability is discussed.