Östrogene Wirkung von Xenobiotika

A number of xenobiotic organic substances are known which, in cases of prenatal exposition, may produce an estrogenic effect leading subsequently to serious reproductive disorders in the male progeny. Damage of this kind which is seen to occur in wildlife populations leads to the assumption that environmental chemicals exerting such estrogenic effects may be responsible for these disorders. Listed here are environmental chemicals which are known to date to exert an estrogenic effect. The article provides a review of papers and hypotheses on the estrogenic effects of xenobiotic substances. This is followed by a discussion concerning the significance of chemical estrogenicity on environmental and chemical policies as well as on the possibilities and limitations of test systems for the verification of estrogenicity.     

Additive und synergistische Kombinationswirkungen von Xenobiotika in subtoxischen Konzentrationen auf menschliche Fibroblasten

The toxic combination effects of xenobiotics of different substance classes were investigated in human fibroblasts. Subtoxic concentrations of 4-chloroaniline enhanced the toxicity of 2,4-dichlorophenoxyacetic acid (2,4-D, dimethylammonium salt) in an additive manner. A mixture of 4-chloroaniline, dicofol and 4-chlorophenol increased the toxicity of 2,4-D synergistically. The concentrations of the components used in the mixture were one third of their ?no observed effect concentrations” (NOEC). The combination of 4-chloroaniline, dicofol and 4-chlorophenol (without 2,4-D) at subtoxic concentrations also showed synergistic effects. The great differences in the lipophilicity of the combined substances might be the cause of the synergistic action.