Key words: poliovirus/cation content/plasma membrane Cation Content in Poliovirus-infected HeLa Cells

Poliovirus-infected HeLa cells increased their permeability to monovalent ions from the third hour post-infection. At that time infected cells lost their content of potassium ions as measured by efflux of the potassium analogue 86Rb+. The rate of release of 86Rb+ from cells increased as infection proceeded, and was not sensitive to ouabain or quinidine, inhibitors of the Na+/K + ATPase and Ca2+-induced K + release system, respectively. The leakage of 86Rb+ was only slightly sensitive to furosemide, an inhibitor of the Na+/K+/C1- cotransport system, suggesting that the mechanism of release involved an increased passive permeability ofthe cell membrane. The calcium content or its efflux did not vary significantly in the infected cells. Neither were there alterations in the intracellular pH throughout infection. 33