L Wang

Publications (2)6.76 Total impact

• Article: Developmental exposure to lead causes inherent changes on voltage-gated sodium channels in rat hippocampal CA1 neurons.

  D Yan, L Wang, F-L Ma, H Deng, J Liu, C Li, H Wang, J Chen, J-L Tang, D-Y Ruan
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  ABSTRACT: In this study, the effects of chronic lead (Pb(2+)) exposure, during day 0 of gestation (E0) to postnatal day 15 (P15), on voltage-gated sodium channel currents (I(Na)) were investigated in CA1 field of the hippocampus (CA1) neurons using the conventional whole-cell patch-clamp technique on rat hippocampal slices. We found that developmental lead exposure increased the activation threshold and the voltage at which the maximum I(Na) current was evoked, caused positive shifts of I(Na) steady-state activation curve, and enlarged I(Na) tail-currents; Pb(2+) delayed the activation of I(Na) in a voltage-dependent manner, prolonged the time course of the fast inactivation of sodium channels; Pb(2+) induced a right shift of the steady-state inactivation curve, accelerated the activity-dependent attenuation of I(Na), but made no significant effects on the time course of the recovery of I(Na) from inactivation and the fraction of inactivated channels. In addition, the co-treatment with alpha-tocopherol (VE), an effective antioxidant and free radical scavenger, completely prevented the aforementioned changes on I(Na). The alterations on I(Na) properties induced by developmental lead exposure were partly different from that in previous acute experiments under the conditions closer to physiological situation, and the process was considered related to the participating of lead in lipid peroxidation reaction, which has been reported to change the conformation and biophysical functions of membrane proteins.
  Neuroscience 06/2008; 153(2):436-45. · 3.38 Impact Factor
• Article: Effects of lead on voltage-gated sodium channels in rat hippocampal CA1 neurons.

  Y Gu, L Wang, C Xiao, F Guo, D-Y Ruan
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  ABSTRACT: In this study, the effects of lead (Pb2+) on voltage-gated sodium channel currents (INa) were investigated in acutely dissociated rat hippocampal CA1 neurons using the conventional whole-cell patch-clamp technique. We found that Pb2+ reduced the amplitudes of INa in a concentration-dependent manner, and the effect could be washed out by extracellular application of 3 mM EGTA. The results also showed that at the concentration of 100 microM, Pb2+ decreased the activation threshold and the voltage at which the maximum INa current was evoked and caused negative shifts of INa steady-state activation curve, and enlarged INa tail-currents; Pb2+ induces a left shift of the steady-state inactivation curve, and delayed the recovery of INa from inactivation, and reduced the fraction of available sodium channels; Pb2+ delayed the activation of INa in a concentration- and voltage-dependent manner, and prolonged the time course of the fast inactivation of sodium channels; activity-dependent attenuation of INa was not altered by Pb2+. It was suggested that Pb2+ might exert its effects on sodium channels by binding a specific site on the extracellular side of sodium channels and dragging the IIS4 voltage sensor outwardly. The interaction of Pb2+ with voltage-dependent sodium channels may lead to change in electrical activity and contribute to worsen the neurotoxicological damage.
  Neuroscience 02/2005; 133(3):679-90. · 3.38 Impact Factor