Monovalent ion permeability of model bilayer membranes based on lipids from tissues of various vertebrates

The ionic permeability of model bilayer membranes prepared from total lipids of the brain, heart, liver, and muscles of four species of higher vertebrates was studies. The electrical conductivity and potential of membranes breakdown were measured in KCl, NaCl, and LiCl solutions. It was found that the permeability for potassium ions of bilayer lipid membranes from the lipids of nervous tissue decreases in the row of poikilothermal vertebrates and increases in mammals. A reverse regularity was observed for membrane stability, which manifested itself as an increase in membrane breakdown in the order fish-amphibian-reptile and a decrease in membrane breakdown in mammalian membranes. It was shown that, in most cases, the the permeability of bilayer lipid membranes for K+ ions is higher than for Na+ and Li+.