Open AccessMethylmercury Effects On Cell Cycle Kinetics
Author(s) -
Vogel D. G.,
Rabinovitch P. S.,
Mottet N. K.
Publication year - 1986
Publication title -
cell proliferation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.647
H-Index - 74
eISSN - 1365-2184
pISSN - 0960-7722
DOI - 10.1111/j.1365-2184.1986.tb00733.x
Subject(s) - methylmercury , cell cycle , chemistry , kinetics , population , cell , andrology , in vitro , biophysics , flow cytometry , incubation , viability assay , microbiology and biotechnology , toxicology , biochemistry , biology , environmental chemistry , medicine , physics , bioaccumulation , environmental health , quantum mechanics
. Methylmercury (MeHg) effects on cell cycle kinetics were investigated to help identify its mechanisms of action. Flow cytometric analysis of normal human fibroblasts grown in vitro in the presence of BrdU allowed quantitation of the proportion of cells in G 1 , S, G 2 and the next G 1 phase. This technique provides a rapid and easily performed method of characterizing phase lengths and transition rates for the complete cell cycle. After first exposure to MeHg the cell cycle time was lengthened due to a prolonged G 1 . At 3, μm MeHg the G 1 phase length was 25% longer than the control. the G 1 /S transition rate was also decreased in a dose‐related manner. Confluent cells exposed to MeHg and replated with MeHg respond in the same way as cells which have not been exposed to MeHg before replating. Cells exposed for long times to MeHg lost a detectable G 1 effect, and instead showed an increase in the G 2 percentage, which was directly related to MeHg concentration and length of exposure. After 8 days at 5 μM MeHg, 45% of the population was in G 2 . the G 2 accumulation was reversible up to 3 days, but at 6 days the cells remained in G 2 when the MeHg was removed. Cell counts and viability indicated that there was not a selective loss of cells from the MeHg. MeHg has multiple effects on the cell cycle which include a lengthened G 1 and decreased transition probability after short term exposure of cycling cells, and a G 2 accumulation after a longer term exposure. There were no detectable S phase effects. It appears that mitosis (the G 2 accumulation) and probably synthesis of some macromolecules in G 1 (the lengthened G 1 and lowered transition probability) are particularly susceptible to MeHg.