Ion transport mediated by copolymers composed of polyoxyethylene and polyoxypropylene.

Academic Article

Abstract

  • Block copolymers composed of polyoxyethylene and polyoxypropylene were found to increase the influx of Na+ and the efflux of K+ from human erythrocytes. They were, however, ineffective at promoting the transport of Ca2+. The size of the ion fluxes induced by the copolymers correlated with their efficacy in stimulating inflammation. These compounds were also found to induce conductance increases in planar lipid bilayers in a nonvoltage dependent and nonstepwise manner. In both experimental systems, ion transport was facilitated only under temperature and ionic-strength conditions in which the polymers form aggregates in aqueous solution. In neither system did the concentration dependence of transport activity exhibit a pronounced cooperativity. These observations are consistent with the view that aqueous monomers of these surface active agents partition into the membrane, where they facilitate the conductive movement of monovalent cations by means of a carrier type mechanism. As a novel class of ionophores, these substances are of practical interest because they can be water soluble and are potentially reversible.
  • Authors

    Published In

    Keywords

  • Biological Transport, Calcium, Cations, Divalent, Electric Conductivity, Erythrocytes, Humans, Lipid Bilayers, Poloxalene, Polyethylene Glycols, Sodium, Temperature
  • Digital Object Identifier (doi)

    Author List

  • Atkinson TP; Bullock JO; Smith TF; Mullins RE; Hunter RL
  • Start Page

  • C20
  • End Page

  • C26
  • Volume

  • 254
  • Issue

  • 1 Pt 1