Equine estrogens (EQs) are steroidal hormones isolated from the urine of pregnant mares and are used in the formulation of human medications. This study initially investigated the embryonic developmental toxicity of equilin (Eq) and equilenin (Eqn) in medaka (Oryzias latipes). Malformations were observed in embryos exposed to nominal concentrations of 1 and 10 mg/L of Eq and Eqn. Delayed hatching was observed at 1 mg/L of Eq. To further investigate the molecular mechanism of developmental toxicity caused by Eq and Eqn, transcriptome and bioinformatics analyses were performed. Among 2016 and 3855 total differentially expressed genes (DEGs), 1117 DEGs overlapped between Eq. (55.4 % of total DEGs) and Eq. (29.0 % of total DEGs). Gene ontology indicated effects in terms related to blood circulation and cell junctions. Pathway analyses using DEGs revealed that both Eq and Eqn treatments at 10 mg/L affected various KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways, such as neuroactive ligand-receptor interaction, mitogen-activated protein kinase signaling, retinol metabolism, and cytokine-cytokine receptor interaction. These results suggest that the disruption of these KEGG pathways is involved in the developmental toxicity of EQs in medaka embryos.
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http://dx.doi.org/10.1016/j.cbpc.2023.109547 | DOI Listing |
Arch Toxicol
January 2025
Department of Ecotoxicology, Helmholtz Centre for Environmental Research-UFZ, Permoserstraβe 15, 04318, Leipzig, Germany.
Testing for developmental toxicity is an integral part of chemical regulations. The applied tests are laborious and costly and require a large number of vertebrate test animals. To reduce animal numbers and associated costs, the zebrafish embryo was proposed as an alternative model.
View Article and Find Full Text PDFCrit Rev Toxicol
January 2025
Product Stewardship, Science & Regulatory, Shell Global Solutions International B.V. The Hague, the Netherlands.
Xylene substances have wide industrial and consumer uses and are currently undergoing dossier and substance evaluation under Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) for further toxicological testing including consideration of an additional neurotoxicological testing cohort to an extended one-generation reproduction toxicity (EOGRT) study. New repeated dose study data on xylenes identify the thyroid as a potential target tissue, and therefore a weight of evidence review is provided to investigate whether or not xylene-mediated changes on the hypothalamus-pituitary-thyroid (HPT) axis are secondary to liver enzymatic induction and are of a magnitude that is relevant for neurological human health concerns. Multiple published studies confirm xylene-mediated increases in liver weight, hepatocellular hypertrophy, and liver enzymatic induction the oral or inhalation routes, including an increase in uridine 5'-diphospho-glucuronosyltransferase (UDP-GT) activity, the key step in thyroid hormone metabolism in rodents.
View Article and Find Full Text PDFToxicol Ind Health
January 2025
Cincinnati, OH, USA.
(E)-1,1,1,2,2,5,5,6,6,6-Decafluoro-3-hexene (HFO-153-10mczz-E) (CASRN 1256353-26-0) is a volatile liquid proposed for use as a new low global-warming potential dielectric fluid in cooling applications. Workplace exposures are expected to be by inhalation exposure. The substance has low acute inhalation toxicity as indicated by a 4-h inhalation LC value of approximately 8000 ppm.
View Article and Find Full Text PDFToxicol Res (Camb)
January 2025
Department of Zoology, Guru Nanak Dev University, Amritsar 143005, India.
Polybrominated diphenyl ethers (PBDEs) have been classified as a new class of persistent organic pollutants by the United Nations Environment Programs in 2009. In environment, PBDEs can undergo the degradation process to form less brominated diphenyl ethers. In the present study, the 96 h LC value for 4-bromodiphenyl ether (BDE-3) was found to be 3.
View Article and Find Full Text PDFRespir Res
January 2025
Department of Obstetrics and Gynecology, C.S. Mott Center for Human Growth and Development, School of Medicine, Wayne State University, 275 E Hancock St, Rm 195, Detroit, MI, 48201, USA.
Current fetal alcohol spectrum disorders (FASD) studies primarily focus on alcohol's actions on the fetal brain although respiratory infections are a leading cause of morbidity/mortality in newborns. The limited studies examining the pulmonary adaptations in FASD demonstrate decreased surfactant protein A and alveolar macrophage phagocytosis, impaired differentiation, and increased risk of Group B streptococcal pneumonia with no study examining sexual dimorphism in adaptations. We hypothesized that developmental alcohol exposure in pregnancy will lead to sexually dimorphic fetal lung morphological and immune adaptations.
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