Kurejová M, Pavlovicová M, Lacinová L'
Institute of Molecular Physiology and Genetics, Centre of Excellence for Cardiovascular Research, Slovak Academy of Sciences, Slovakia.
Gen Physiol Biophys. 2007 Sep;26(3):234-9.
We have investigated the permeability of the Cav3.1 channel for Ca2+ and different monovalent cations and the block of the currents by Mg2+ ions. In the absence of extracellular divalent cations, the Cav3.1 channel was more permeable for Na+ than for Cs+ and impermeable for NMDG+. Monovalent currents were inhibited by Mg2+ of near physiological concentration by three orders of magnitude more effectively than the Ca2+ current. Inhibition of outward, but not inward current by Mg2+ was voltage-dependent. Furthermore, magnesium slowed down channel deactivation presumably by interacting with an open channel state.
我们研究了Cav3.1通道对Ca2+和不同单价阳离子的通透性以及Mg2+离子对电流的阻断作用。在没有细胞外二价阳离子的情况下，Cav3.1通道对Na+的通透性高于对Cs+的通透性，而对NMDG+则不通透。单价电流被接近生理浓度的Mg2+抑制的效率比Ca2+电流高三个数量级。Mg2+对外向电流而非内向电流的抑制作用是电压依赖性的。此外，镁可能通过与开放通道状态相互作用来减缓通道失活。
