Metergoline inhibits the neuronal Nav1.2 voltage-dependent Na(+) channels expressed in Xenopus oocytes

  • Acta Pharmacol Sin. 2014 Jul;35(7):862-8. doi: 10.1038/aps.2014.30.
Jun-Ho Lee  1 Jian Liu  2 Minkyu Shin  2 Moochang Hong  2 Seung-Yeol Nah  3 Hyunsu Bae  2
Affiliations
  • 1. 1] Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea [2] Present address: Duke University Medical Center, Durham, NC 27710, USA.
  • 2. Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 130-701, Republic of Korea.
  • 3. College of Veterinary Medicine, Konkuk University, Seoul 130-701, Republic of Korea.
Abstract

Aim: Metergoline is an ergot-derived psychoactive drug that acts as a ligand for serotonin and dopamine receptors. The aim of this study was to investigate the regulatory effects of metergoline on the neuronal Nav1.2 voltage-dependent Na(+) channels in vitro.

Methods: Xenopus oocytes were injected with cRNAs encoding rat brain Nav1.2 α and β1 subunits. Voltage-activated Na(+) currents were recorded using two-electrode voltage clamp technique. Drugs were applied though perfusion.

Results: Both metergoline and lidocaine reversibly and concentration-dependently inhibited the peak of Na(+) currents with IC50 values of 3.6 ± 4.2 and 916.9 ± 98.8 μmol/L, respectively. Metergoline (3 μmol/L) caused a 6.8 ± 1.2 mV depolarizing shift of the steady-state activation curve of the Na(+) currents, and did not alter the inactivation curve. In contrast, lidocaine (3 μmol/L) caused a 12.7 ± 1.2 mV hyperpolarizing shift of the inactivation curve of the Na(+) currents without changing the steady-state activation curve. Both metergoline and lidocaine produced tonic and use-dependent inhibition on the peak of Na(+) currents.

Conclusion: Metergoline exerts potent inhibition on the activity of neuronal Nav1.2 channels, which may contribute to its actions on the central nervous system.

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