Overview
- Wang, G.K. et al. (2008) Mol. Pharmacol. 73, 940.
- Alomone Labs Ranolazine inhibits NaV1.5 channels heterologously expressed in HEK-293 cells.A. Time course of the cardiac NaV1.5 (expressed in HEK-293 cells) current inhibition by 200 and 500 µM Ranolazine (#R-110). Currents were elicited by application of voltage ramps from a holding potential of -100 mV to 0 mV (50 msec). B. Superimposed example traces of current responses before and during perfusion of 200 and 500 µM Ranolazine as indicated.
- Alomone Labs Ranolazine inhibits NaV1.4 channels heterologously expressed in Xenopus oocytes cells.A. Time course of the skeletal NaV1.4 current inhibition by 100, 200 and 500 µM Ranolazine (#R-110). Currents were elicited by application of voltage ramps from a holding potential of -100 mV to +30 mV (100 msec). B. Superimposed example traces of current responses before and during perfusion of 100, 200 and 500 µM Ranolazine as indicated.
Voltage-gated Na+ (NaV) channels are essential for the generation and propagation of action potentials in excitable membranes. The NaV channel protein contains four homologous domains (D1-D4), each with six transmembrane segments (S1-S6). There are 9 isoforms (NaV1.1-1.9) found among mammalian excitable tissues, including central nervous system, peripheral nervous system, skeletal muscle, and heart1.
Ranolazine is an antianginal and anti-ischemic drug that is used in patients with chronic angina2. Ranolazine displays a broad pharmacological profile on a number of targets and has complex electrophysiological effects in myocardium3. This drug seems to preferentially reduce the persistent late cardiac NaV1.5 Na+ currents with a 50% inhibitory concentration (IC50) of 15 μM, whereas normal transient Na+ currents are less affected, with an IC50 of 135 μM4. The binding site of ranolazine in human cardiac Na+ channels is probably the same as the local anesthetic (LA) receptor within the inner cavity of the Na+ channel, because a single mutation in this channel (e.g. residue hNaV1.5-F1760A) alters the ranolazine binding affinity drastically4.