title: Cation selectivity of the resting membrane of squid axon.
abstract: Permeability constant ratios among monovalent cations were studied in the resting membrane of a giant axon of a Pacific squid,Loligo opalescens, by observing the relationship between the membrane potential and the ion concentration.The average permeability ratios are: Tl, 1.8; K, 1.0; Rb, 0.72; Cs, 0.16; Na, <0.08; Li, <0.08. These permeability ratios suggest that neither valinomycin nor nonactin are adequate models for the sites producing the resting permeability in the axonal membrane.Cyclic polyetherbis(t-butyl cyclohexyl) 18-crown-6 does not increase the permeability ratioP Cs/P K except when applied at concentrations (5×10(-5) M) at which the surfactant properties of this molecule may become significant.
authors.affiliation: Department of Physiology, U.C.L.A., 90024, Los Angeles, California.
authors.forename: S
authors.initials: S
authors.lastname: Hagiwara
authors.forename: D C
authors.initials: DC
authors.lastname: Eaton
authors.forename: A E
authors.initials: AE
authors.lastname: Stuart
authors.forename: N P
authors.initials: NP
authors.lastname: Rosenthal