Mercuric Chloride Activates Latent, Anion-Dependent Cation Transport Systems in the Plasma Membrane of Ehrlich Ascites Tumour Cells

Abstract

Electronic cell sizing of Ehrlich ascites tumour cells is presented as a biological test system for assessment of membrane associtated effects of toxic compounds. Ehrlich ascites tumour cells readjust their cell volume after osmotic swelling in hypotonic media. This regulatory process (Regulatory Volume Decrease, RVD) involves a net loss of KCl from the cells. Addition of HgCl2 (1 .mu.M) results in a Cl--dependent acceleration of RVD in hypotonic medium. Cells in isotonic Cl- containing medium shrink upon addition of HgCl2 due to a Cl--dependent net loss of K+. In addition, a Cl--dependent net uptake of Na+ was also seen in the presence of HgCl2. It is concluded that HgCl2 activates a latent K+, Cl- cotransport as well as Na+, Cl- cotransport in Ehrlich cells.