Some electrical properties of cerebroside and lecithin bilayer membranes

Electrical potentials of cerebroside and lecithin bilayers in the presence of Na+, Ca2+, and Sr2+ were measured. Calculated membrane specific resistances were about 10(7) ohm cm2. Calculated transference numbers for Na+, Ca2+, and Sr2+ were between 0.5 and 0.6, and were higher in both membranes than in free solution. Thus membranes are slightly cation selective. Specific conductances and transference numbers were then used to calculate ionic flux of membranes. Sodium ions had a much greater ionic flux in both membranes than calcium and strontium ions. The results indicate that the electrical properties of cerebroside and lecithin bilayer membranes are compatible with the structures of those membranes.