Endocrine bioassay

MacLatchy, D., S. Courtenay, C. Rice and G. Van Der Kraak. Development of a short-term reproductive endocrine bioassay using steroid hormone and vitellogenin endpoints in the estuarine mummichog (Fundulus heteroclitus). Environ. Toxicol. Chem. 22 996-1008, 2003. 

Several recent expert reviews and workshops have discussed the effects of endocrine disruption on wildlife and especially invertebrate species. These include the EU workshop on the impact of endocrine disrupters on human health and wildlife (Weybridge, 1996), the lEH workshop (Leicester, May 1997), the Environment Agency Consultative report (January 1998) and the Tyndall Forum at the Royal Institution (February 1998). They have concluded that endocrine disruption may have far-reaching adverse consequences for biodiversity and the sustainability of natural ecosystems. More comprehensive bioassay systems are required to identify and assess chemicals alleged to produce endocrine modulating effects. 

Studies also suggested that IL-6 causes endothelial cell dysfunction and decrease of prostacyclin production. Soluble IL-6 receptors seem to play a modulating and enhancing role in IL-6 activity (FI 8). The incidence of detection appears to be less influenced by the method of assay, as either ELISA or bioassay techniques yield consistent results, with a high correlation between these techniques. IL-6 values may be more constant and endocrine-like than those values of TNF and IL-1. 

An example of a TIE approach is that described by Desbrow et al. [7]. In this work, the endocrine disrupting activity detected in effluents of seven UK WWTPs by means of a yeast-based screening assay [52] was mainly attributed to the presence of estradiol, estrone, and ethynylestradiol. However, to assess the estrogenic activity different bioassays may be used, e.g., the yeast-based recombinant estrogen receptor-reporter assay (YES), the MCF-7 cell proliferation (E-screen), and the estrogen receptor-mediated chemically activated... 

Episodic pollution events can adequately be addressed by acute toxicity bioassays, however these are not sufficient to investigate the water quality for delayed toxicity effects of chemicals present. Chronic effects of pesticides can include carcinogenicity, teratogenicity, mutagenicity, neurotoxicity, and reproductive effects (endocrine disruption). 

Endocrine Effects. Thyroid hyperplasia and pituitary cysts were observed in rats, but not mice, in a chronic bioassay study with endrin administered in the feed (NCI 1978). Treon et al. (1955) found diffuse degeneration of the adrenal glands in rats dosed with >1.25 mg/kg/day in their feed for 2 years however, the adrenal effects were absent at the 0.25 mg/kg/day dose. There has been no evidence of endocrine effects in occupationally exposed human populations. 

Endocrine Effects. Thyroid hyperplasia and pituitary cysts were observed in rats, but not in mice, in a chronic bioassay study with endrin administered in the feed (NCI 1978). There has been no evidence of endocrine effects in occupationally exposed populations. 

The designation potential endocrine disrupter has been proposed for chemical products with an endocrine-disruption ability that is demonstrated in an in vitro assay but not confirmed in an in vivo animal model. To date, most of the available information on chemical products with endocrine disrupter activity has been generated by in vitro experiments [10]. Various existing tests and bioassays of very different types have been proposed by distinct international bodies to identify hormonal... 

The development of new tests and bioassays is likely to lengthen the list of endocrine disrupters. Recent research on hormonal disruption has not only investigated estrogens and androgens as agonists and antagonists but also considered the development of the individual and the presence of compounds that interfere in other hormonal systems, such as the thyroid system. 

Other Systemic Effects. Endocrine lesions related to 1,2-dibromoethane exposure were reported in the NCI (1978) gavage bioassay. These consisted of adrenal cortical cell degeneration in a small number of exposed male and female Osborne-Mendel rats. The possibility exists that this adrenal change represents a secondary (stress-related) effect rather than a primary effect of 1,2-dibromoethane exposure. 

Houtman, C.J., Cenijn, P.H., Hamers, T., Lamoree, M.H., Legler, J., Murk, A.J., Brouwer, A. (2004). Toxicological profiling of sediments using in vitro bioassays with emphasis on endocrine disruption. Environmental Toxicology... 

Rogers JM, Denison MS (2000) Recombinant cell bioassays for endocrine dismptors development of a stably transfected human ovarian cell line for the detection of estrogenic and anti-estrogenic chemicals. In Vitr Mol Toxicol 13 67-82... 

Simoni M, Weinbauer GF, Nieschlag E (1993) Molecular composition of two different batches of urofollitropin Analysis by immunofluorometric assay, radioligand receptor assay and in vitro bioassay. J Endocrin Invest 16 21-27 Starring PL, Gaines Das RE (1989) The International Standard for pituitary FSH collaborative study of the Standard and of four other purified human FSH preparations of differing molecular composition by bioassays, receptor... 

Since the responses observed in this bioassay (and others) can be the result of a variety of effects, not only on the endocrine system, but also on the nervous and other systems (19), a selected group of JHs, AJHs and pesticides (Table I) were used in developing this bioassay in an effort to test and eliminate responses due to non-AJH compounds. Likewise, it is important in any successful bioassay to simply and rapidly eliminate inactive and inappropriate compounds (i.e. non-AJHs). Thus, the first steps in our bioassay attempt to exclude non-AJHs and inactive compounds, leaving the later steps for the confirmation of AJH activity to those few compounds that are most likely AJHs. 

---