Palmitoyl-L-carnitine acts like ouabain on voltage, current, and contraction in guinea pig ventricular cells.

摘要: We previously showed that palmitoyl-L-carnitine (L-PC) inhibits the Na/K pump current (INa/K). In present report, we test hypothesis L-PC, like ouabain, should increase myocyte shortening. Membrane potentials or ionic currents were recorded simultaneously with cell shortening in single guinea pig ventricular myocytes at room temperature (22 degrees C). Like L-PC (1 microM) reversibly depolarized resting membrane, decreased action potential duration, and increased amplitude of contractions. Neither nor ouabain had a significant effect on Ca (ICa). When during ramp voltage clamp, membrane shifted inward voltages negative to -20 mV outward more positive voltages. Similar toxic concentrations induced transient aftercontractions. At inhibit INa/K, acted produce characteristic effects potentials, currents, contractions unrelated changes ICa. reduces surface charge erythrocytes (C. Gruver A. J. Pappano, Mol. Cell. Cardiol. 25: 1275-1284, 1993), speculate INa/K by this mechanism.