Effects of hydrogen peroxide on sodium current in acutely isolated rat hippocampal CA1 neurons.
The effects of hydrogen peroxide (H2O2) on sodium currents (Na+ currents) in freshly dissociated rat hippocampal neurons were studied using the whole-cell patch-clamp techniques. H2O2 caused a reversible increase of the voltage-activated Na+ currents in a concentration- and voltage-dependent manner. The half-increasing concentration (EC50) of H2O2 on Na+ currents was 10.79 microM. In addition, 10 microM H2O2 shifted the steady-state inactivation curve of Na+ currents toward positive potential (control Vh = -64.58 +/- 1.22 mV, H2O2 Vh = -53.55 +/- 0.94 mV, n = 10, P < 0.01 without changing the slope factor). However, the steady-state activation curve was not affected. These results indicated that H2O2 could increase the amplitudes of Na+ currents and change the inactivation properties of Na+ channels even in very low concentration.
Meng
Ziqiang
Z
Institute of Environmental Medicine and Toxicology, Shanxi University, Wucheng Road 36, Taiyuan 030006, PR China. zqmeng@sxu.edu.cn
Nie
Aifang
A
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000633:toxicity*; D066298:In Vitro Techniques; D015640:Ion Channel Gating / Q000187:drug effects* / Q000502:physiology; D018408:Patch-Clamp Techniques; D017966:Pyramidal Cells / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D015222:Sodium Channels / Q000502:physiology*
D015222:Sodium Channels; D006861:Hydrogen Peroxide