Dose-dependent excretion of DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene) in rats.

Dose-dependent excretion of p,p'DDE in rats was investigated. p,p'DDE itself was the major excreta in rats. But some o,p'isomer of DDE was detected in feces by GC-MS analysis. The excretion of p,p'DDE after a single administration was modified by its dose level. The time pattern of p,p'DDE excretion agrees well with the modified Hill equation. The value of the equilibrium constant (K') increases in proportion to time t after p,p'DDE administration. Using the modified Hill equation and the linear K' equation, the excretion rate of p,p'DDE during the experimental time t can be estimated. The estimated p,p'DDE excretion rate in feces agrees well with the measurements.