[The effect of lead on cells cultivated in vitro. I. Acute effects (author's transl)].

Static suspension cultures of L-A cells, a subline of L929 mouse fibroblasts, were exposed to inorganic lead salts. Lead caused a growth inhibition which was independent of the anion used and which could be prevented by the addition of Ca-EDTA. The LD50 was approximately 1 mM when exposing the cells for 2 days and 2 X 10(-4) M when treating them for 7 days. The minimal growth inhibiting dose was in the range of 2 to 4 X 10(-5) M. Concomitant with the dose-dependent inhibition of proliferation the fraction of cells synthesizing DNA and the mitotic rate were lowered, suggesting a block in the G1 phase of the cell cycle. Energy metabolism appeared affected as evidenced by a rise in lactate production. Lactate dehydrogenase release was in the control range. Lead induced an increase in cell size and, at higher concentrations, cellular vacuolations.