Vitellogenin as a biomarker for estrogenic effects in brown trout, Salmo trutta: Laboratory and field investigations

Abstract

The sensitivity of juvenile brown trout towards estrogenic chemicals (17beta-estradiol [E2], estrone [E1], 17alpha-ethinylestradiol [EE2], 4-tert-octylphenol [OP], and n-butylparaben [BP]) was tested in laboratory experiments with plasma and liver vitellogenin concentrations as endpoints. Vitellogenin concentrations were also assessed in juvenile brown trout collected in streams affected by agricultural runoff and discharges from scattered houses in the open land. In the laboratory, juvenile brown trout were exposed to the chemicals in flow-through tanks for 7 to 12 d and concentration-response relationships for the induction of vitellogenin synthesis were obtained. The actual exposure concentrations were determined by liquid chromatography-mass spectrometry. The median plasma vitellogenin concentration in first year control brown trout reared in recirculated groundwater was 165 ng/ml with 783 ng/ml as the highest value. The median effective concentration (EC50) values for vitellogenin induction (based on plasma concentrations) were 3.7 ng EE2/L, 15 ng E2/L, 88 ng E1/L, 68 microg BP/L, and 7 microg OP/L. Median effective concentrations derived from liver vitellogenin concentrations were similar. The 166 brown trout caught in the field were mainly first and second year fish and a few third year fish. Plasma vitellogenin concentrations were below 1000 ng/L in 146 of the fish, between 1000 ng/L and 4234 ng/L in 19 fish and 5.3 x 10(6) ng/L in one male fish. Vitellogenin concentrations did not differ between first and second year fish, but were elevated in third year fish. The data may indicate that juvenile (<2 years) trout with plasma vitellogenin concentrations above 1000 ng/ml have had their vitellogenin synthesis induced by exposure to estrogens in the environment. Plasma and liver vitellogenin concentrations were closely correlated in brown trout with elevated vitellogenin concentrations. It is noteworthy, however, that exposure to synthetic estrogens (EE2, BP, and OP) resulted in higher liver concentrations (for the same plasma concentration) than exposure to the natural estrogens E1 and E2.

Development of an enzyme‐linked immunosorbent assay for quantifying vitellogenin in Pacific salmon and assessment of field exposure to environmental estrogens

“…The range of VTG levels and the magnitude of VTG increase in the current study were similar to those reported in a marine study on wild flounder in Japan [34] and in a freshwater study on brown trout in Denmark [35]. The range and magnitude were also similar to the lower end of those reported for wild flounder in the United Kingdom or the Netherlands [36,37] and in freshwater studies involving either wild roach [38] or caged rainbow trout [39] held for three to four weeks downstream of sewage effluent outfalls in the United Kingdom.…”

Probabilistic ecological hazard assessment of parabens using Daphnia magna and Pimephales promelas

“…Propylparaben elicited vitellogenin induction in Japanese medaka at 9.9 mg/L, but lower concentrations were not tested [20]. Additionally, butylparaben has been shown to induce plasma vitellogenin production in male brown trout at 134 mg/L and higher [45]. Although studies have not observed estrogenic effects at levels that are at concentrations that have been observed in effluent or surface waters, exposure values are limited in number and in types of sites sampled.…”

Sex hormone concentrations and gonad histology in brown trout (Salmo trutta) exposed to 17β-estradiol and bisphenol A

“…Exposure of several species of fish to estrogen and estrogenic compounds has also caused a reduction in GSI and an inhibition of the sperm cell development (Jobling et al 1996;Van den Belt et al 2001. In a recent field survey it has been confirmed that in second year Danish brown trout, male (5.6 ± 4.6; n = 17) GSI is generally higher, but also much more variable than female (0.28 ± 0.13; n = 17) GSI (Bjerregaard et al 2008). …”