Effects of methylcholanthrene and benzanthracene on blastogenesis and aryl hydrocarbon hydroxylase induction in splenic lymphocytes from three inbred strains of mice.

The effects of polycyclic aromatic hydrocarbons (PAH) such as benzanthracene (BA) and methylcholanthrene (MCA) on 3H-thymidine incorporation and aryl hydrocarbon hydroxylase (AHH) induction were assayed in mitogen-activated and non-activated splenic lymphocyte cultures derived from three strains of mice (C57BL, C3H and DBA/2). Results of three separate experiments on blastogenesis and the substrate induction of AHH were statistically significant. In mitogen-activated and non-activated lymphocytes from C57BL and C3H mice (AHH responsive strains) the percentage of blastogenesis induced by BA or MCA was higher than in lymphocytes from the non-responsive strain (DBA/2). On the basis of the PAH concentrations used MCA and BA were similar as inducers of blastogenesis and of AHH activity. AHH induction was measurable only in mitogen-activated lymphocytes and showed a non-linear relation to blastogenesis. In responsive strains, 10 microM oF BA or 1.5 microM of MCA induced AHH 2-5 fold, while in non-responsive mice induced AHH was very close to the basal level. This difference between the level of induction of lymphoblast formation and AHH in responsive and non-responsive strains of mice may be related to different subpopulations of lymphocytes in spleen or other lymphatic organs.