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 us ed to assess the quality of surface water in Germany, is suitable to indica te the presence of endocrine-disrupting chemicals. An electrophoretic metho d was used to determine estrogen-induced protein in fish serum (presumed vi tellogenin). This method was tested by exposing juvenile L. idus to 17 alph a-ethinylestradiol, 17 beta-estradiol and estrone. Nominal concentrations o f the steroid were compared with concentrations determined analytically by using GC/MS techniques. Under how-through conditions, 7 days of exposure to 6 ng/l EE2 significantly induced serum vitellogenin in juvenile L. idus. I n juvenile rainbow trout (Oncorhynchus mykiss) 4 ng/l EE2 induced significa ntly elevated levels of serum vitellogenin. In Danio rerio oral application of 40 mu g 4-nonylphenol/fish per day during a 3-week exposure period caus ed a major increase of serum vitellogenin. Physiological protein induction could also be measured in Abramis brama, Cyprinus carpio, Oncorhynchus myki ss, Perca fluviatilis, Rutilus rutilus obtained from natural habitats and i n Rhodeus sericeus. The minimum amount of blood required for electrophoreti c analysis was 1 mu l which should allow monitoring of small sized fish spe cies as well as juvenile fish. (C) 1999 Elsevier Science B.V. All rights re served.