METAL-IONS AFFECT NEURONAL MEMBRANE FLUIDITY OF RAT CEREBRAL-CORTEX

The effect of various metal ions on neuronal membrane fluidity was exa mined using oxypropyl)-2-ethyl-4,4-dimethyl-3-oxazolidinyloxy, which h as been used for the examination of membrane fluidity in hydrophobic a reas by electron spin resonance spectrometry. Potassium, cobalt, calci um, magnesium, nickel, copper, ferric, and aluminium ions decreased th e membrane fluidity while ferrous ions increased it at each high conce ntration. Sodium and zinc ions had no effect. Ethylenediaminetetraacet ic acid decreased membrane fluidity at high concentrations. Nicardipin e lowered membrane fluidity and flunarizine elevated it at each high c oncentration. There was no change in membrane fluidity by other calciu m antagonists, nimodipine and nifedipine.