Block of L-Type Ca2+ Current by Beauvericin, a Toxic Cyclopeptide, in the NG108-15 Neuronal Cell Line
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- 作者：Sheng-Nan Wu ; Hsinyo Chen ; Yen-Chin Liu ; and Hung-Ting Chiang
- 刊名：Chemical Research in Toxicology
- 出版年：2002
- 出版时间：June 2002
- 年：2002
- 卷：15
- 期：6
- 页码：854 - 860
- 全文大小：98K
- 年卷期：v.15,no.6(June 2002)
- ISSN：1520-5010
文摘
The effects of beauverficin, a cyclodepsipeptide compound, on ion currents in a mouseneuroblastoma and rat glioma hybrid cell line, NG108-15, were investigated with the aid ofthe whole-cell voltage-clamp technique. Beauvericin (0.3-100 
M) reversibly produced aninhibition of L-type voltage-dependent Ca2+ current (ICa,L) in a concentration-dependent manner.Beauvericin caused no change in the overall shape of the current-voltage relationship of ICa,L.The IC50 value of beauvericin-induced inhibition of ICa,L was 4 M. Neither gabapentin (30M) nor 
-conotoxin GVIA (3 M) had effects on ICa,L. Beauvericin (30 M) shifted the steady-state inactivation curve of ICa,L to more negative membrane potentials by approximately -15mV. The inhibitory effects of beauvericin on ICa,L exhibited tonic and use-dependent characteristics. Beauvericin also suppressed ICa,L evoked by repetitive action potential waveformseffectively. However, beauvericin (30 M) had no effect on delayed rectifier K+ current inNG105-18 cells. Under current-clamp configuration, beauvericin reduced the firing frequencyof action potentials. Therefore, this study indicates that beauvericin is a relatively specificinhibitor of L-type Ca2+ current in NG108-15 cells.
M) reversibly produced aninhibition of L-type voltage-dependent Ca2+ current (ICa,L) in a concentration-dependent manner.Beauvericin caused no change in the overall shape of the current-voltage relationship of ICa,L.The IC50 value of beauvericin-induced inhibition of ICa,L was 4 M. Neither gabapentin (30M) nor -conotoxin GVIA (3 M) had effects on ICa,L. Beauvericin (30 M) shifted the steady-state inactivation curve of ICa,L to more negative membrane potentials by approximately -15mV. The inhibitory effects of beauvericin on ICa,L exhibited tonic and use-dependent characteristics. Beauvericin also suppressed ICa,L evoked by repetitive action potential waveformseffectively. However, beauvericin (30 M) had no effect on delayed rectifier K+ current inNG105-18 cells. Under current-clamp configuration, beauvericin reduced the firing frequencyof action potentials. Therefore, this study indicates that beauvericin is a relatively specificinhibitor of L-type Ca2+ current in NG108-15 cells.