Swann A C
Department of Psychiatry and Behavioral Sciences, University of Texas Medical School, Houston 77225.
Alcohol. 1990 Mar-Apr;7(2):91-5. doi: 10.1016/0741-8329(90)90067-m.
Fluoride ions inhibit several membrane enzymes in a manner that is dependent on membrane fluidity. Inhibition of (Na+, K+)-ATPase by fluoride ions may be a model for membrane effects on (Na+, K+)-ATPase. Therefore, we have examined properties of fluoride inhibition relative to interactions with ethanol and to ligands that alter sensitivity of (Na+, K+)-ATPase to ethanol. Fluoride ion reduced the K0.5 and Hill coefficient for K+ activation of p-nitrophenylphosphatase. Ethanol decreased the Hill coefficient and apparent affinity for inhibition of phosphatase activity by fluoride ion while dimethylsulfoxide had the opposite effects. Chronic ethanol treatment in vivo, which produced behavioral tolerance, had effects on fluoride inhibition opposite to those of ethanol in vitro. Inhibition by fluoride therefore may provide a useful marker for physiologic or pharmacologic conditions that alter regulation of (Na+, K+)-ATPase by membrane properties.
氟离子以一种依赖于膜流动性的方式抑制几种膜酶。氟离子对（钠，钾）-ATP酶的抑制作用可能是膜对（钠，钾）-ATP酶影响的一个模型。因此，我们研究了氟抑制的特性，涉及与乙醇的相互作用以及改变（钠，钾）-ATP酶对乙醇敏感性的配体。氟离子降低了对硝基苯磷酸酶钾激活的K0.5和希尔系数。乙醇降低了希尔系数以及氟离子对磷酸酶活性抑制的表观亲和力，而二甲基亚砜则有相反的作用。体内慢性乙醇处理产生行为耐受性，其对氟抑制的影响与体外乙醇的影响相反。因此，氟抑制可能为改变（钠，钾）-ATP酶膜性质调节的生理或药理状况提供一个有用的标志物。
