Electrophoretic determination of estrogen-induced protein in fish exposed to synthetic and naturally occurring chemicals

In a first step we investigated whether Leuciscus idus, a fish routinely used to assess the quality of surface water in Germany, is suitable to indicate the presence of endocrine-disrupting chemicals. An electrophoretic method was used to determine estrogen-induced protein in fish serum presumed vitellogenin.. This method was tested by exposing juvenile L. idus to 17a-ethinylestradiol, 17b-estradiol and estrone. Nominal concentrations of the steroid were compared with concentrations determined analytically by using GCrMS techniques. Under flow-through conditions, 7 days of exposure to 6 ngrl EE2 significantly induced serum vitellogenin in juvenile L. idus. In juvenile rainbow trout Oncorhynchus mykiss. 4 ngrl EE2 induced significantly elevated levels of serum vitellogenin. In Danio rerio oral application of 40 mg 4-nonylphenolrfish per day during a 3-week exposure period caused a major increase of serum vitellogenin. Physiological protein induction could also be measured in Abramis brama, Cyprinus carpio, Oncorhynchus mykiss, Perca flu¨iatilis, Rutilus rutilus obtained from natural habitats and in Rhodeus sericeus. The minimum amount of blood required for electrophoretic analysis was 1 ml which should allow monitoring of small sized fish species as well as juvenile fish.