Metabolism of DDT in different tissues of young rats

The bioconcentration and distribution pattern of p, p'-DDT [1,1,1-trichloro-2,2-bis (2chlorophenyl-4-chlorophenyl)-ethane] and its main metabolites (p, p'-DDD [1,1-dichloro2,2-bis (4-chlorophenyl)ethane] and p, p'-DDE [1,1-dichloro-2,2-bis (4-chlorophenyl) ethylene]) in adipose tissue, liver, brain, kidney, thymus, and testis were examined in young rats after 10 days of intraperitoneal injection of 50 and 100 mg of p, p'-DDT/kg of body weight. Analyses were performed by high-resolution gas chromatography. p, p'-DDT was found to be accumulated in a dose-dependent manner with the highest concentration in adipose tissue. However, in brain, the accumulation of pesticide was low and remained unchanged at the higher dose. This difference may relate to the protective role of the blood-brain barrier, which limits the access of the xenobiotic in the cerebral compartment, and to the differential tissue lipid composition. Although tissues concentration of p, p'-DDE and p, p'-DDD correlated positively to total p, p'-DDT levels, the active role in detoxification of pollutants may explain why p, p'-DDD is more abundant in liver than in the rest of organs. On the contrary, in brain, the concentration of p, p'-DDE is higher than that of p, p'-DDD, suggesting that the metabolism of the parent insecticide proceeds via more than one pathway.