Inducible protective processes in animal systems VI. Cross-adaptation and the influence of caffeine on the adaptive response in bone marrow cells of mouse

The effect of caffeine (CAF) (a replicative DNA synthesis inhibitor) given as pre-, inter- and post-treatments on the ethyl methanesulfonate (EMS)-ind uced adaptive response in in vivo mouse bone marrow cells was studied in or der to understand the influence of CAF on the adaptive response. The pre-tr eatment was given 4 h before a combined treatment with EMS (conditioning challenge) and in another set CAF was given as a conditioning dose and 4 h later the cells were challenged with a high. dose of EMS. In the inter-trea tment, CAF (40 mg/kg body wt) was administered 2 or 4 h after the condition ing dose of EMS and 6 or 4 h later the cells were challenged with a high do se of EMS. Similarly, in the post-treatment experiments, CAF was injected 6 , 12 or 18 h after a combined treatment with EMS. The results revealed that the pre-, inter- and post-treatments with CAF significantly reduced the fr equency of chromosomal aberrations compared with the challenge and combined treatments with EMS. It is interesting to note that CAF pre-treatment resu lted in a much greater reduction in chromosomal aberrations compared with t he inter- and post-treatments. Thus, this is an example of cross-adaptation induced by CAF in EMS-treated in vivo mouse bone marrow cells and the resu lts also demonstrate an influence of CAF on the adaptive response.