The use of anabolic agents in food producing animals is prohibited within the EU since 1988 (96/22/EC directive). The control of the illegal use of natural steroid hormones in cattle is still an exciting analytical challenge as far as no definitive method and non-ambiguous analytical criteria are available. The ability of gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) to demonstrate the administration of 17beta-estradiol to bovine has been investigated in this paper. By comparison of 13C/12C isotopic ratio of main urinary estradiol metabolite, i.e. 17alpha-estradiol, with two endogenous reference compounds (ERCs), i.e. dehydroepiandrosterone (DHEA) and 5-androstene-3beta,17alpha-diol, the differentiation of estradiol metabolite origin, either endogenous or exogenous, has been proved to be achievable. After treatment, the delta(13)C(VPDB)-values of 17alpha-estradiol reached -27 per thousand to -29 per thousand, whereas delta13CVPDB-values of DHEA remained between -13 per thousand and -20 per thousand depending on the diet, maize and grass, respectively. A significant difference of delta13CVPDB between ERCs and 17alpha-estradiol was measurable over a period of 2 weeks after estradiol ester administration to the animal.
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http://dx.doi.org/10.1016/j.chroma.2005.07.042 | DOI Listing |
Nicotine Tob Res
January 2025
Masonic Cancer Center, University of Minnesota, 420 Delaware Street SE, Minneapolis, MN.
Introduction: Hormonal contraceptives (HCs), which contain synthetic forms of estrogen (i.e., ethinyl estradiol) and/or progesterone (i.
View Article and Find Full Text PDFToxicol Appl Pharmacol
January 2025
School of Pharmacy, Southwest Medical University, Luzhou, Sichuan 646000, China; Luzhou New Drug Evaluation and Research Center, Luzhou, Sichuan 646000, China. Electronic address:
Aristolochic acid I (AAI), the most prominent component of aristolochic acids and found in nearly all aristolochic herbs, has been demonstrated significant nephrotoxicity. In this study, an acute nephrotoxicity model of AAI mice was established by a single dose injection of AAI. It was observed that there are differences of the sensitivity to AAI nephrotoxicity in female and male mice, with male mice exhibiting nephrotoxic effects even at lower doses.
View Article and Find Full Text PDFJ Hazard Mater
January 2025
Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok 10210, Thailand; Center of Excellence on Environmental Health and Toxicology (EHT), OPS, Ministry of Higher Education, Science, Research and Innovation, Bangkok, Thailand. Electronic address:
2-Ethylhexyl diphenyl phosphate (EHDPP) is a replacement flame-retardant commonly found in several environmental matrices and human biospecimens. Although some adverse effects of EHDPP have been identified, the endocrine-disrupting effects of EHDPP and its key metabolites on the human estrogen receptor (ER) are largely unknown. Herein, we report for the first time that EHDPP, at concentrations found in the environment and humans, significantly promoted estrogenic activity and synergized with 17β-estradiol-induced ER transactivation.
View Article and Find Full Text PDFInt Immunopharmacol
January 2025
Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, China. Electronic address:
Background: Circulating levels of the female hormone estrogen has been associated with the development of Parkinson's disease (PD), although the underlying mechanism remains unclear. Immune homeostasis mediated by peripheral regulatory T cells (Treg) is a crucial factor in PD. The aim of this study was to explore the effects of estrogen deficiency on neuroinflammation and neurodegeneration in a rodent model of PD, with particular reference to Treg.
View Article and Find Full Text PDFJ Nanobiotechnology
January 2025
Key Laboratory of Human Genetics and Environmental Medicine, Xuzhou Medical University, Xuzhou, 221004, China.
Fullerenols, a water-soluble polyhydroxy derivative of fullerene, hold promise in medical and materials science due to their unique properties. However, concerns about their potential embryotoxicity remain. Using a pregnancy mouse model and metabolomics analysis, our findings reveal that fullerenols exposure during pregnancy not only significantly reduced mice placental weight and villi thickness, but also altered the classes and concentrations of metabolites in the mouse placenta.
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