(E)4-[4-N,N-DIMETHYLAMINOPHENYL]BUT-3-EN-2-ONE (DMAP) TREATMENT INHIBITS THE RADIATION-INDUCED MICRONUCLEUS FORMATION IN BONE-MARROW OF BALB C MICE/

The frequency of micronucleated polychromatic (MPCE) and normochromati c erythrocytes (MNCE) and polychromatic/normochromatic erythrocyte rat io (P/N ratio) was studied in the bone marrow Of BALB/c mice administe red with 20 mg/kg body weight of (E)4-[4-N,N-dimethylaminophenyl]but-3 -en-2-one (DMAP), a phenylbutenone derivative, 30 min before exposure to different doses of Co-60 gamma-radiation. A dose-dependent increase in the frequency of MPCE and MNCE was observed in double-distilled wa ter (DDW) or oil + irradiated and DMAP + irradiated groups. The freque ncy of MPCE and MNCE was significantly less in the DMAP + irradiated g roup when compared to the DDW or oil + irradiated groups at all the ir radiation doses studied. The P/N ratio declined with increasing radiat ion dose in DDW or oil + irradiated and DMAP + irradiated groups. The inhibitory effect of irradiation on the P/N ratio was less in the DMAP + irradiated group as compared to the DDW or oil + irradiated groups, as evidenced by the higher P/N ratio in the former than the latter. T he P/N ratio was significantly higher in the DMAP + irradiated group f rom 1 Gy irradiation onwards. The dose-response relationship was linea r-quadratic for MPCE, MNCE and P/N ratio for all the groups studied.