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Recommendations for Reducing the USE of Fish and Amphibians in Endocrine-Disruption Testing of Biocides and Plant Protection Products in Europe Criteria for determining the endocrine-disrupting (ED) properties of biocide (European Union [EU] Regulation 2017/2100) and plant protection product (PPP) active substances (EU Regulation 2018/605) entered into force on 6 June and 10 November 2018, respectively. In the present article, we estimate the number of fish and amphibians required for ED testing, based on registered PPPs and biocides in Europe. 1 Estimated number of animals required for ED testing of registered pesticide and biocide active substances, based on range-finding and definitive testing, and adjusted for failure rates. [Extracted from the article]

Many studies about endocrine pollution in the aquatic environment reveal changes in the reproduction system of biota. We analysed endocrine activities in two rivers in Southern Germany using three approaches: (1) chemical analyses, (2) invitro bioassays, and (3) invivo investigations in fish and snails. Chemical analyses were based on gas chromatography coupled with mass spectrometry. For invitro analyses of endocrine potentials in water, sediment, and waste water samples, we used the E-screen assay (human breast cancer cells MCF-7) and reporter gene assays (human cell line HeLa-9903 and MDA-kb2). In addition, we performed reproduction tests with the freshwater mudsnail Potamopyrgus antipodarum to analyse water and sediment samples. We exposed juvenile brown trout (Salmo trutta f. fario) to water downstream of a wastewater outfall (Schussen River) or to water from a reference site (Argen River) to investigate the vitellogenin production. Furthermore, two feral fish species, chub (Leuciscus cephalus) and spirlin (Alburnoides bipunctatus), were caught in both rivers to determine their gonadal maturity and the gonadosomatic index. Chemical analyses provided only little information about endocrine active substances, whereas the invitro assays revealed endocrine potentials in most of the samples. In addition to endocrine potentials, we also observed toxic potentials (E-screen/reproduction test) in waste water samples, which could interfere with and camouflage endocrine effects. The results of our invivo tests were mostly in line with the results of the invitro assays and revealed a consistent reproduction-disrupting (reproduction tests) and an occasional endocrine action (vitellogenin levels) in both investigated rivers, with more pronounced effects for the Schussen river (e.g. a lower gonadosomatic index). We were able to show that biological invitro assays for endocrine potentials in natural stream water reasonably reflect reproduction and endocrine disruption observed in snails and field-exposed fish, respectively. [ABSTRACT FROM AUTHOR]

The follicle is a unique micro-environment within which the oocyte can develop and mature to a fertilisable gamete. The aim of this study was to investigate the ability of a panel of follicular parameters, including intrafollicular steroid and metabolomic profiles and theca, granulosa and cumulus cell candidate gene mRNA abundance, to predict the potential of bovine oocytes to develop to the blastocyst stage in vitro. Individual follicles were dissected from abattoir ovaries, carefully ruptured under a stereomicroscope and the oocyte was recovered and individually processed through in vitro maturation, fertilisation and culture. The mean (± s.e.m.) follicular concentrations of testosterone (62.8 ± 4.8 ng mL[sup -1]), progesterone (616.8 ± 31.9 ng mL[sup -1]) and oestradiol (14.4 ±2.4 ng mL[sup -1]) were not different (P > 0.05) between oocytes that formed (competent) or failed to form (incompetent) blastocysts. Principal-component analysis of the quantified aqueous metabolites in follicular fluid showed differences between oocytes that formed blastocysts and oocytes that degenerated; L-alanine, glycine and L-glutamate were positively correlated and urea was negatively correlated with blastocyst formation. Follicular fluid associated with competent oocytes was significantly lower in palmitic acid (P = 0.023) and total fatty acids (P = 0.031) and significantly higher in linolenic acid (P = 0.036) than follicular fluid from incompetent oocytes. Significantly higher (P < 0.05) transcript abundance of LHCGR in granulosa cells, ESR1 and VCAN in thecal cells and TNFAIP6 in cumulus cells was associated with competent compared with incompetent oocytes. [ABSTRACT FROM AUTHOR]