[Influence of various enzyme inductors and combinations of inductors on DDT residue elimination in rats].

A study was under-taken to investigate the influence of pretreatments with various hepatic microsomal enzyme inducers on the elimination of DDT residues in rats previously contaminated with p,p' -DDT at 5 mg/kg/day, during 20 days. The following inducers were used : phenobarbital (50 a mg/kg/day, i.p.), 3,4-benzopyrene (20 mg/kg/day, s.c.) and norethandrolone (20 mg/kg/day, s.c.), all given during 14 consecutive days. Each inducer was administered singly or in combination with the other two according to a 2 X 2 X 2 factorial experiment. The animals were then sacrificed for the measurement of p,p' -DDT, p,p' -DDD and p,p' -DDE residues in the blood, brain, abdominal fat, liver and kidneys. The results show that phenobarbital lowers markedly the concentration of total residues in the fat tissue and brain and that norethandrolone brings about a reduction of the residues in the blood, brain and kidneys, but not in the fat tissue. On the opposite, 3,4-benzopyrene produces an increase of the residues in the brain, liver and kidneys. Phenobarbital thus appears to be more efficacious than the other two inducers in facilitating the elimination of DDT residues from the fat tissue. In addition, it appears that under the experimental conditions used during this investigation, the elimination of DDT residues is not further accelerated by combining the inducers one with each other.