DDT congener effects on secondary sex coloration in the reed frog Hyperolius argus: a partial evaluation of the Hyperolius argus endocrine screen.

Organochlorine compounds such as o,p'DDT can mimic estrogen effects. We compared the effects of o,p'DDT and six other DDT congeners to the effects of estradiol by comparing in vivo color changes in the reed frog (Hyperolius argus). Premature female color pattern induction in H. argus is specific to estrogens and the current study suggests that this assay has potential for use in discriminating between xenobiotic estrogens and non-estrogens. Animals were treated at forelimb emergence and maintained in treated solution until final evaluation. Estradiol, o,p.DDT (0.1 microg/ml), o,p'DDE (1 microg/ml) and o,p'DDD (1 microg/ml) prematurely induced adult female coloration patterns in juvenile animals, whereas p,p'DDT, p, p'DDE and p,p'DDD did not.