Abstract
The effects of extracellular anions (10-150 mM, added as Na salts to normal growth medium) on the growth of Chinese hamster V-79 cells were examined. Additions of NaCl and NaNO3 at concentrations greater than 60 mM reduced the growth rate dose-dependently. Several other anions also inhibited cell growth in the decreasing order of potency, SCN->NO2-> NO3->Br->Cl->gluconate->glutamate->Mes-. When the added anions were removed, the growth rate was restored to the control rate. Cell survival was markedly reduced by the addition of SCN-, but was less affected by other anions (Cl-, NO3-and NO2-) of comparable potency. The respective syntheses of cellular DNA and protein, as estimated from the incorporation of [3H]-thymidine and [14C]leucine, also decreased with the increase in the concen-tration (60-120 mM) of anions added, the order of potency being SCN-> NO2->NO3-> Cl-. After anion-treatment, the cellular Na+ concentration increased and the cellular Cl-concentration decreased in the order of SCN-> NO2->NO3-, Cl-, but, the cellular K+ concentration did not change signifi-cantly. These data suggest that changes in extracellular anions affect cell growth and survival, probably through changes in the intracellular Na+ or Cl-concentration and in the rates of protein and/or DNA synthesis.
