A comparison of the delayed outward potassium current between the nucleus ambiguus and hippocampus: sensitivity to paeonol

作者：Chin TsangYang; Leung Yuk Man; Hsu Sheng Feng; MacDonald Iona; Wang Mei Ling; Lin Jaung Geng; Hung Shih Ya^*; Chen Yi Hung^*

来源：European Journal of Pharmacology, 2016, 784: 49-60.

DOI：10.1016/j.ejphar.2016.04.057

• Paeonol
• Hippocampal neuron
• Potassium current
• Action potentials

Whole-cell patch-clamp recordings investigated the electrophysiological effects of 2'-hydroxy-4'-methoxyacetophenone (paeonol), one of the major components of Moutan Cortex, in hippocampal CA1 neurons and nucleus ambiguus (NA) neurons from neonatal rats as well as in lung epithelial H1355 cells expressing Kv2.1 or Kv1.2. Extracellular application of paeonol at 100 mu M did not significantly affect the spontaneous action potential frequency, whereas paeonol at 300 mu M increased the frequency of spontaneous action potentials in hippocampal CA1 neurons. Paeonol (300 mu M) significantly decreased the tetraethylammonium-sensitive outward current in hippocampal CA1 neurons, but had no effect upon the fast-inactivating potassium current (IA). Extracellular application of paeonol at 300 mu M did not affect action potentials or the delayed outward currents in NA neurons. Paeonol (100 mu M) reduced the Kv2.1 current in H1355 cells, but not the Kv1.2 current. The inhibitor of Kv2, guangxitoxin-1E, reduced the delayed outward potassium currents in hippocampal neurons, but had only minimal effects in NA neurons. We demonstrated that paeonol decreased the delayed outward current and increased excitability in hippocampal CA1 neurons, whereas these effects were not observed in NA neurons. These effects may be associated with the inhibitory effects on Kv2.1 currents.

• 出版日期2016-8-5
• 单位中国医科大学