A model for the effects of potential and external K+ concentration on the Cs+ blocking of inward rectification.
Inward rectification in starfish egg cell membranes is blocked by external Cs+, the degree of blocking being an increasing function of hyperpolarizing potentials and of the external concentration of K+. While the effect of K+ and the particular functional dependence of blocking on potential are difficult to reconcile with a one-ion pore model, both features can be accounted for assuming that the pore has at least two sites and tat a considerable fraction of the blocked pores is simultaneously occupied by a Cs+ ion in the inner site and by a K+ in the outer one.
D000818:Animals; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology*; D002586:Cesium / Q000494:pharmacology*; D005260:Female; D008433:Mathematics; D008954:Models, Biological; D010063:Ovum / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000494:pharmacology*; D013215:Starfish
D002586:Cesium; D011188:Potassium