Thyroid-stimulating hormone (TSH): Measurement of intracellular, secreted, and circulating hormone in Xenopus laevis and Xenopus tropicalis

Korte, Joseph J.; Sternberg, Robin M.; Serrano, Jose A.; Thoemke, Kara; Moen, Scott M.; Lillegard, Kathryn E; Hornung, Michael W.; Tietge, Joseph E.; Degitz, Sigmund J.

doi:10.1016/j.ygcen.2011.02.017

Cited by 26 publications

(10 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As anuran metamorphosis is a thyroid‐dependent process, basal levels of follicular cell hypertrophy and hyperplasia were anticipated findings in control larvae at or around the metamorphic climax (NF stage 61) when they were killed in the current study (Grim et al ., ). The stimulus for both follicular cell hypertrophy and hyperplasia is increased circulating levels of thyroid‐stimulating hormone (TSH) (Tietge et al ., ), concentrations of which are highest in the X. laevis pituitary between NF stages 58 and 62 (Korte et al ., ). Although not completely understood, the rapid elevation in TSH associated with metamorphic climax occurs despite a concomitant rise in circulating TH, which would otherwise be expected to suppress pituitary TSH production via the classic HPT negative feedback mechanism (Buckbinder and Brown, ; Sternberg et al ., ).…”

Section: Discussionmentioning

confidence: 97%

Effect of triclosan on anuran development and growth in a larval amphibian growth and development assay

et al. 2017

View full text Add to dashboard Cite

A larval amphibian growth and development assay was performed to evaluate the potential effects of environmentally-relevant concentrations of triclosan (TCS) on amphibian development and growth. Xenopus laevis were exposed to TCS 0.0 (control), 6.3, 12.5 and 25.0 μg l (estimated maximum tolerable concentration) until 10 weeks post-metamorphosis. At median metamorphosis time (Nieuwkoop and Faber stage 62), five larvae per replicate were collected for snout-vent length, hind limb length and body weight measurements, and histopathological examination of thyroid glands. Endpoints evaluated at test termination were based on draft guidance (USEPA, ) and included: survival; snout-vent length; body weight; gender; nuptial pad development (males); and liver, kidney, gonad and gonadal ducts histopathology. Exposure to TCS did not decrease survival, induce general signs of toxicity, affect median metamorphosis time or alter sex ratios. Exposure to TCS 12.5 and 25 μg l increased growth during the metamorphic stages relative to the control, but did not influence growth during the post-metamorphic phase. Overall, several statistically significant findings were found in larvae exposed to TCS, such as a decrease in the prevalence of stage 3 Müllerian ducts in the anterior trunk sections of TCS 25.0 μg l dose group females as compared to controls; most were not considered toxicologically relevant. Copyright © 2017 John Wiley & Sons, Ltd.

show abstract

Section: Discussionmentioning

confidence: 97%

Effect of triclosan on anuran development and growth in a larval amphibian growth and development assay

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Arias Torres et al (2016) (reference 15412 in Annex B -) validated a competitive chemiluminescence enzyme immunoassay (ECLIA) for ovarian steroid in Rhinella arenarum using a method previously developed for human samples. Korte et al (2011) Chemical analysis Chang et al (2010) quantified the estrogens (E1, 17β-E2, 17α-E2) in African clawed frogs (Xenopus laevis), a standard test species (see reference 1407 in Annex B -) using liquid chromatographyelectrospray tandem mass spectrometry (LC-ESI-MS/MS). It required to 0.3-1ml samples of frog plasma and reported a linear calibration range between 0.5-1000 ng/mL.…”

Section: Enzyme-linked Immunosorbent Assay (Elisa)mentioning

confidence: 99%

“…TSH was extracted from the sample matrices using phosphate/Tween-20 with heating, however how effective this method is unclear as they did not conduct TSH spiked sample extraction recoveries. The LOD of the TSH ELISA was 0.22 ng using 10-20 µL of sample, with inter-assay cv of 5% and intra-assay cv of 5.01% and 5.09% (Korte et al 2011 The present document has been produced and adopted by the bodies identified above as author(s). This task has been carried out exclusively by the author(s) in the context of a contract between the European Food Safety Authority and the author(s), awarded following a tender procedure.…”

Section: B212 Hypothalamic-pituitary-thyroid Axis Hormonesmentioning

confidence: 99%

Data collection in support of the Endocrine Disruption (ED) assessment for non‐target vertebrates

Martin

Ermler

McPhie

et al. 2020

EFS3

View full text Add to dashboard Cite

To harmonise vertebrate OECD Test Guidelines for endocrine disruption testing between mammalian and non-mammalian test species, additional Estrogen, Androgen, Thyroid and Steroidogenesis (EATS) modality endpoints in non-mammalian models need to be assessed. These would mean for example the addition of hormonal measurements in fish, birds and amphibians. Furthermore, a better reporting of gross pathology findings for birds would also be considered advantageous for the assessment of endocrine disrupting properties. To facilitate adoption of additional measures, guidance on how to perform, report and evaluate these new endpoints is required. In this report, a variety of methods including a systematic evidence map, an extensive literature review and a survey of ecotoxicology laboratories were adopted to collect data on the topic. The systematic evidence map uncovered a range of methods for measuring sex and thyroid hormones in fish, birds and amphibians, although methods for measuring sex-hormones in fish, were by far, the most frequently encountered in the literature and laboratory survey. However, there are still considerable gaps in knowledge for: optimum sample timing for hormonal measurement (diurnal, developmental stage, etc.), issues with inherent variability, low sample volume (plasma/serum), test species selection, possible impacts of housing/diet/stress. The extensive literature review revealed that although gross pathology and histopathology have been used to investigate the effects of endocrine disrupting chemicals in birds, there are no standardised methods for assessment or interpretation, although relative weight of endocrine organs is frequently used as a gross pathology metric. Reports of how histopathology was assessed varied considerably. From the survey, few contract laboratories are experienced in conducting the avian test guideline and these types of pathology techniques. Recommendations for future work with non-mammalian taxa include: investigating the optimal time (or timings) for measuring hormones, developing non-invasive hormone measuring techniques, gaining knowledge of baseline/control hormonal data, and further developing guidance on conducting and assessing gross pathology and histopathology in birds.

show abstract

“…Figure modified from Crofton (2008). a Quantification of plasma TSH levels in Xenopus tropicalis (Korte et al 2011). b Direct quantification of intrafollicular concentrations of T 4 in zebrafish embryos (Thienpont et al.…”

Section: Use Of Alternative Species and In Vitro Assays In An Aop Framentioning

confidence: 99%

“…As a result, serum TH levels are a reliable predictor of HPT axis disruption across species. Methods to measure circulating TSH in X. laevis have been recently developed and successfully applied in a toxicological context (Korte et al 2011; Tietge et al 2012). Zebrafish embryos have also been used to directly quantify thyroid disruption effects through immunodetection of TH levels in intrafollicular cells (Thienpont et al 2011).…”

Section: Use Of Alternative Species and In Vitro Assays In An Aop Framentioning

confidence: 99%

Current Perspectives on the Use of Alternative Species in Human Health and Ecological Hazard Assessments

Perkins

Ankley

Crofton

et al. 2013

Environ Health Perspect

Self Cite

View full text Add to dashboard Cite

Background: Traditional animal toxicity tests can be time and resource intensive, thereby limiting the number of chemicals that can be comprehensively tested for potential hazards to humans and/or to the environment.Objective: We compared several types of data to demonstrate how alternative models can be used to inform both human and ecological risk assessment.Methods: We reviewed and compared data derived from high throughput in vitro assays to fish reproductive tests for seven chemicals. We investigated whether human-focused assays can be predictive of chemical hazards in the environment. We examined how conserved pathways enable the use of nonmammalian models, such as fathead minnow, zebrafish, and Xenopus laevis, to understand modes of action and to screen for chemical risks to humans.Results: We examined how dose-dependent responses of zebrafish embryos exposed to flusilazole can be extrapolated, using pathway point of departure data and reverse toxicokinetics, to obtain human oral dose hazard values that are similar to published mammalian chronic toxicity values for the chemical. We also examined how development/safety data for human health can be used to help assess potential risks of pharmaceuticals to nontarget species in the environment.Discussion: Using several examples, we demonstrate that pathway-based analysis of chemical effects provides new opportunities to use alternative models (nonmammalian species, in vitro tests) to support decision making while reducing animal use and associated costs.Conclusions: These analyses and examples demonstrate how alternative models can be used to reduce cost and animal use while being protective of both human and ecological health.Citation: Perkins EJ, Ankley GT, Crofton KM, Garcia-Reyero N, LaLone CA, Johnson MS, Tietge JE, Villeneuve DL. 2013. Current perspectives on the use of alternative species in human health and ecological hazard assessments. Environ Health Perspect 121:1002–1010; http://dx.doi.org/10.1289/ehp.1306638

show abstract

Thyroid-stimulating hormone (TSH): Measurement of intracellular, secreted, and circulating hormone in Xenopus laevis and Xenopus tropicalis

Cited by 26 publications

References 14 publications

Effect of triclosan on anuran development and growth in a larval amphibian growth and development assay

Effect of triclosan on anuran development and growth in a larval amphibian growth and development assay

Data collection in support of the Endocrine Disruption (ED) assessment for non‐target vertebrates

Current Perspectives on the Use of Alternative Species in Human Health and Ecological Hazard Assessments

Contact Info

Product

Resources

About