Balaton Limnological Research Institute of the Hungarian Academy of Sciences, Tihany, Hungary.
Environ Monit Assess. 1992 Jul;22(1):57-72. doi: 10.1007/BF00402655.
Effects of Cu(2+), Pb(2+) and Zn(2+) were studied on voltage-activated Na-, Ca-, and K-currents in snail neurons. It was found that: 1. In normal physiological saline Cu(2+), Pb(2+) and Zn(2+) ions exerted complex changes on the total ionic currents; 2. All three metal ion have depressed the inward Na-currents but with different K D , moreover Pb (2+) increased Na-current at low concentrations (5 μM); 3. The inward Ca-current was also reduced. The sequence of the blocking effect of metals was different: Pb>Cu>Zn, however the steady-state inactivation was influenced only by Cu(2+); 4. Outward currents were decreased in all neurons by Cu(2+), but the effects of Pb(2+) and Zn(2+) were either depression or enhancement in different indentified neurons; 5. The possibility of binding heavy metals to wide variety of membrane proteins and the observed effects on different ionic channels suggest that the metal effect is complex and cannot be taken as a specific one to a single channel type or site of location.
研究了 Cu(2+)、Pb(2+)和 Zn(2+)对蜗牛神经元电压激活的 Na+、Ca2+和 K+电流的影响。结果发现：1. 在正常生理盐水中，Cu(2+)、Pb(2+)和 Zn(2+)离子对总离子电流产生了复杂的变化；2. 这三种金属离子均抑制内向 Na 电流，但 KD 不同，此外 Pb(2+)在低浓度（5 μM）时增加 Na 电流；3. 内向 Ca 电流也减少。金属的阻断效应顺序为：Pb>Cu>Zn，但稳态失活仅受 Cu(2+)影响；4. Cu(2+)使所有神经元的外向电流减少，但 Pb(2+)和 Zn(2+)对不同鉴定神经元的影响是抑制或增强；5. 重金属与多种膜蛋白结合的可能性以及对不同离子通道的观察到的影响表明，金属效应复杂，不能将其视为对单一通道类型或位置的特异性影响。
