Studies on Membrane Model: I. Surface Pressure and Surface Potential oi pure Phospholipid Monolayers*

Using highly purified phospholipid preparations, the effects of various salts on the surface pressure and the surface potential of the phospholipid monolayer are studied. The results are in good agreement with those obtained by several authors. The surface potential of cardiolipin decreases at high compression region in the presence of acetylcholinc. The results of preliminary experiments on the action of acetyl-choline show that the decrease of the surface potential of cardiolipin monolayer is enhanced by Ca, but suppressed by Na or hexamethonium bromide.