The usefulness of P450 as a biomarker and an assessing tool for the impact of environmental endocrine disrupting chemicals on the wild animals was studied.
Chlorinated hydrocarbon (CHC) levels in the blubber of Larga seals and Ribbon seals collected from the coastal waters of Hokkaido, Japan were determined in order to assess the hormonal effects of CHC exposure. In these animals, CYP1A expression levels were coincided with CHC accumulation levels. We also tried to isolate P450 isoforms such as CYP1A and CYP3A subfamilies, which contributed to elimination of xenobiotic and to catabolism of steroid hormone in mammals. We detemined the sequences and enzymatic characters of CYP1A1, CYP1A2 and CYP3A forms.
We also investigated the CHC effects on xenobiotic metabolisms and hormonal homeostasis in fish. We collected male and female carps from Hikiji river, where raw sewage containing dioxins had been released into river water for seven and a half years. The expression levels of CYP1A subfamily were coincided with dioxin accumulation levels. In contrast, estrogen level and GSI (gonadal somatic index) value were reduced in female carps collected from dioxin-contaminated river.