Effect of HgCl2 on rat kidney cells in primary culture.

Single cell suspensions, obtained from rat kidneys, were cultured with various concentrations of HgCl2 for different times to examine the effects on cellular synthetic activity. Unexpectedly, the RNA synthesis of kidney cells was stimulated with low doses of HgCl2, whereas it was inhibited with higher doses. Even at a higher dose, RNA synthesis was stimulated during early incubation but was inhibited during longer incubations. Thus, the effect of mercury showed a biphasic pattern both in dose-response and time-response relationships. Moreover, once the cells were exposed to HgCl2 for a certain period, RNA syntehsis was irreversibly inhibited. Since RNA synthesis was inhibited earlier than DNA or a protein synthesis, the RNA synthesizing system appeared most susceptible. Without HgCl2, by the time DNA synthesis reached its maximum, protein and RNA synthesis had already declined. In contrast, RNA synthesis of HgCl2-treated cells remained at its maximal level and showed no decline when DNA synthesis reached its peak.