ALTERATIONS OF HISTONE PHOSPHORYLATION IN RAT SPLEEN-CELLS AFTER TREATMENT WITH THE AROMATIC AMINE, 4,4'-METHYLENE-BIS(2-CHLOROANILINE)

Alterations of the phosphorylation pattern of histones by the carcinog en, 4,4'-methylene-bis(2-chloroaniline) (MOCA) were investigated using rodent spleen cells. Spleen cells were isolated from Sprague-Dawley r ats and treated with either 5, 10, 25, or 50 mu M MOCA or acetone vehi cle controls for 1, 2, 4, or 8 hours. Cells were incubated with P-32-p hosphoric acid, and histones from these cells were fractionated utiliz ing two-dimensional polyacrylamide gel electrophoresis. Marked stimula tion of histone phosphorylation was observed with the 10 mu M MOCA tre atment. A transient decrease in histone phosphorylation was observed a t the 1 and 2 hour time points followed by a marked stimulation at 4 h ours.