title: Studies of the antiproliferative action of inorganic lead in relation to the phases of the rat glial cell cycle.
abstract: Inorganic lead inhibited proliferation of the C6 glial cell line with an IC(50) value of 5 x 10(-5)m-lead chloride. Cells released from a 48-hr exposure to 10(-4)m-lead chloride did not show a coherent [(3)H]thymidine incorporation on entering the S phase of the cell cycle, which suggested that they lacked synchrony. Lead did not appear to compromise DNA biosynthetic capability, since synchronous cells, obtained by mitotic selection, coherently entered S phase after a 14-hr exposure to 10(-4)m-PbCl(2). Cells maintained for 48 hr in 10(-4)m-PbCl(2) exhibited morphologies typical of an asynchronous population; however, 1 hr after release, selection of mitotic figures indicated that 35% of these cells had entered M phase. We conclude that inorganic lead has no specific antiproliferative site of action but may contribute to a lengthening of the cell cycle, the most pronounced effect being in late G2.
authors: Department of Pharmacology, University College, Belfield, Dublin 4, Ireland.
authors: G R
authors: GR
authors: Cookman
authors: C M
authors: CM
authors: Regan