Endocrine modulation, inhibition of ovarian development and hepatic alterations in rainbow trout exposed to polluted river water.

Under laboratory conditions, female rainbow trout were exposed to graded concentrations of water from the River Lambro, a polluted tributary of the River Po, and to the effluent of a large wastewater treatment plant which flows into the River Lambro. In field exposures, trout were held in cages in the River Po upstream and downstream from the confluence of the River Lambro. After 10-day (laboratory) and 30-day (laboratory and field) exposures, trout were examined for several chemical, biochemical and histological endpoints.

Immunohistochemical localization of hydroxysteroid sulfotransferase and sulfatase in the brain of Rana esculenta tadpoles.

Sulfation plays a major role in regulating the activity of various neurosteroids, including pregnenolone and dehydroepiandrosterone. The present report describes the immunohistochemical distribution of two enzymes involved in the control of neurosteroid sulfation, hydroxysteroid sulfotransferase (HST) and unconjugated steroid enzyme sulfatase (STS), in the brain of the European green frog Rana esculenta during development. HST and STS immunoreactivity were detected from stage VIII-XII.

Endocrine disrupting chemicals (EDC) with (anti)estrogenic and (anti)androgenic modes of action affecting reproductive biology of Xenopus laevis: II. Effects on gonad histomorphology.

A number of man-made chemicals has been shown to mimic endogenous hormones and to induce alterations of reproductive physiology in wild populations. Of particular importance are compounds that mimic estrogens and androgens (and their antagonists), because of their central role in reproductive function. In this study, male and female adult South African clawed toads (Xenopus laevis) were exposed to ethinylestradiol (EE2), tamoxifen (TAM), methyldihydrotestosterone (MDHT) and flutamide (FLU) as (anti)estrogenic and (anti)androgenic model compounds, respectively, at a concentration of 10(-8) M, and to water from the river Lambro (LAM), a contaminated watercourse from Northern Italy.