Membrane potentials across the bovine lens capsule in vitro

Abstract

Membrane potentials of the lens capsule were studied in vitro for electrolytes of various types: KCl, NaCl, LiCl, MgCl 2, CaCl 2, LaCl 3, Na 2SO 4, K 2SO 4, MgSO 4 and HCl. The lens capsule had positively fixed charges. The parameter l − ∗/(l + ∗ + l − ∗) for an electrolyte in the membrane phase was equal to the parameter l −/(l + + l −) for the electrolyte in bulk solution. Theoretical results at c 2/c 1 = constant coincided with experimental data in c 2 > Θ , but experimental values of the membrane potential deviated systematically below theoretical curves as c 2 decreased in c 2 < Θ , where l − ∗ and l − ∗ are the ionic mobilities in the membrane phase of positive and negative ions, respectively, l + and l − are the ionic mobilities in bulk solutions of positive and negative ions, respectively, c 2 is the higher concentration of bulk solution (moles/l), and Θ is the effective charge density of the membrane (moles/l). The interaction parameter between dissociated ions of the membrane and ions of the bulk solution is discussed.