Figure 5.
Rapamycin affects hERG1a/1b channel inactivation in lipotoxic HEK293 cells. (A) Experimental protocol: hERG1a/1b channel gating mechanisms were determined in HEK293 cells under control conditions, and after pre-exposure to lipotoxicity for 2 h, using the illustrated voltage protocols. Exemplar current traces (B–D) and a graph of τinactivation (E) measured under the indicated conditions. τinactivation was determined by fitting single exponential functions to the decaying phase of currents at voltages ranging from −40 to +40 mV. Pre-exposure to RAP prevented the slowing of τinactivation due to lipotoxicity. The hERG1a/1b channels’ recovery from the voltage-dependent inactivation (F–H), activation (I), and deactivation (J–M) kinetics were essentially unaltered under lipotoxic conditions. (* statistical significance at p < 0.05).