Effect of 3 µM C16-CAR on I_KS.

<p><b>A</b>,I_KS-V curves of the current at the end of the pulse (<b>Aa</b>) and peak tail current (<b>Ab</b>)<b>. B,</b> Typical examples of families of currents in the absence (<b>Ba</b>) and presence of C16-CAR (<b>Bb</b>).</p

Computer simulation of the effects of LCAC on I_KR and the human ventricular action potential.

<p><b>A</b>, families of currents mimicking I_KR with or without acyl-CARs. <b>B</b>, action potential profile in the absence of acylcarnitine(black line) or the presence of a physiological concentration of 3 µM LCAC (red line).</p

Effect of application of intra- or extracellular acyl-CARs on I_hERG deactivation time constants.The hERG current was fitted to a two exponential function (see Methods for details).

<p>The values of tau1 and tau2 are given in ms. Values were obtained when the membrane potential returned to −55 mV after stepping to −10 mV for 5s. *p<0.05, ** p<0.01.</p

Effect of extracellularacyl-CARs on I_hERG.

<p>I_hERG-V relationships,in all graphs, the filled squares represent the current in the absence of acyl-CAR in the pipette (control, n = 12 cells). <b>Aa</b>, effect of 3 µM C8-CAR (empty circles, n = 8 cells) or 3 µM C10-acyl-CAR (filled circles, n = 7 cells); <b>Ab</b>, typical example of C8-CAR (red) compared with PSS (black). <b>Ba,</b> effect of 3 µM C18-CAR (filled circles, n = 9 cells) on I_hERG-V relationship. The inset shows the effect of 3 µM C18-CAR on end-pulse hERG current elicited by a depolarisation to −10 mV from a holding voltage of −70 mV, obtained on a representative cell (the arrows indicate the current obtained at −10 mV during an IV protocol, see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041686#s2" target="_blank">Methods</a>), ***, p<0.001. **, p<0.01.<b>Bb</b>, typical example of C18-CAR (red) compared with PSS (black).</p

Concentration-dependent acceleration of I_hERG inactivation induced by C18-CAR.

<p>The records were obtained in 3 different cells. The current obtained in presence of C18-CAR is shown in red.</p

Effect of extracellular C16 free fatty acid either alone or in combination with C16-CAR on I_hERG deactivation time constants.

<p>Values obtained when the membrane potential returned to −55 mV after stepping to the voltage indicated in the left column in mV for 5 s. The current was fitted to a two exponential function (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0041686#s2" target="_blank">Methods</a>). The values of tau1 and tau2 are expressed in ms. *p<0.05, **P<0.01, *** P<0.001.</p

Effect of C16-CAR on I_K1.

<p><b>A</b>, mean current measured at −120 mV and normalized to the current in PSS (n = 7 cells). <b>B</b>, typical example of I_K1 elicited by a ramp of voltage between −120 and +40 mV, with (red) or without (black) 10µM C16-CAR.</p

The effect of extracellular C16 or C16-CAR on deactivation kinetics of I_hERG, when membrane potential returned to −55 mV from a 5sto −10 mV.

<p>** p<0.01.</p

Effect of extracellular C18-CAR on hERG activation and availability.

<p><b>A</b>. Activation curve in PSS (squares): V_½  =  −20.3±0.1 mV (n = 10); in the presence of 1 µM C18-CAR (circles): −22.8±0.1 mV (n = 8); in the presence of 3 µM C18-CAR (diamonds): −30.0±0.3 mV (n = 8) and in the presence of 10 µM C18-CAR (triangles): −31.9±0.9 mV (n = 4). <b>B</b>. Availability curve in PSS (squares): V_½  =  −40.9±2.3 mV (n = 8); in the presence of 1 µM C18-CAR (circles): V_½ =  −36.2±3.1 mV (n = 8); in the presence of 3 µM C18-CAR (triangles): V_1/2 =  −34.8±1.4 mV (n = 8) and in the presence of 10 µM C18-CAR (diamonds): V_1/2 =  −35.6±2.1 mV.</p

Effect of different concentrations of extracellular C18-CAR on I_hERG deactivation time constants.

<p>Values obtained when the membrane potential returned to −55 mV after stepping to −10 mV for 5 s. *p<0.05, **P<0.01, *** P<0.001.</p