Inhibitory Effect of Ethanol on Voltage-Dependent Potassium Currents in Single Aortic Smooth Muscle Cells

乙醇在單一主動脈平滑肌細胞的電壓依賴型鉀電流之抑制作用

吳勝男(Sheng-Nan Wu) ； 趙俊迪(Chun-Ti Chao)

《The Kaohsiung Journal of Medical Sciences》 11卷9期 (1995/09) Pp. 514-520

https://doi.org/10.6452/KJMS.199509.0514

摘要

本研究在於探討乙醇在單一主動脈平滑肌細胞中電壓依賴型鉀電流的作用。主動脈平滑肌細胞是從天竺鼠分離而來。緊密細胞膜膜片箝制支術合併完整細胞模式為主要研究方法。乙醇在500mM會可逆性的抑制電壓依賴型短暫向外鉀電流、自發性短暫振動性鉀電流、和穩定性鉀電流，而50mM的乙醇則無作用。從自發性短暫振動電流的強度組織分佈圖發現，乙醇對於該電流的強度和頻率都有顯著的抑制作用。既然電壓依賴型鉀離子通道抑制會導致細胞的興奮性增加，因此乙醇產生的電壓依賴型鉀電流的抑制現象可以用來解釋它引起的血管收縮作用。

並列摘要

The effect of ethanol on voltage-dependent K+ currents was examined in single aortic smooth muscle cells. The aortic smooth muscle cells were isolated from guinea pigs. The tight-sal patch clamp technique in whole cell configuration was employed. Ethanol (500 mM) reversible inhibited voltage-dependent transient outward K+ current, the spontaneous transient oscillatory K+ current (STOC) and steady-state K+ current, whereas ethanol (50 mM) did not produce any change in these K+ currents. When the peak-height amplitudes of STOC were analyzed, the application of ethanol (50 mM) was noted to produce significant inhibition on both amplitude and frequency of STOC evoked at the holding potential of + 10 mV. The results shown in the present study indicate that ethanol-induced inhibition of the voltage-dependent K+ channel, which is not required for the elicitation of either GTP-binding protein(s) or inositol triphosphate, may contribute to its vasoconstrictor effect because the inhibition of the voltage-dependent K+ channel may lead to the increase of cell excitability in vascular smooth muscle.

並列關鍵字

ethanol ； potassium curent ； smooth muscle cells