Pyrethroid insecticides, the most commonly used insecticides worldwide, are suspected endocrine-disrupting chemicals. But their interactions with hormone receptors are still unclear. The present study intended to evaluate and compare the hormone receptor (estrogen receptor [ER], androgen receptor [AR], and thyroid hormone receptor [TR]) activities of nine pyrethroids (cycloprothrin, cyfluthrin, cyhalothrin, cypermethrin, deltamethrin, etofenprox, fenvalerate, permethrin, and tetramethrin) and their metabolites (3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropne carboxylic acid [DCCA] and 3-phenoxybenzoic acid [3-PBA]) using receptor-mediated luciferase reporter gene assays. Of the 11 compounds tested, four showed very weak ER agonistic activities and six displayed antiestrogenic effects, among which cyhalothrin and DCCA possessed the most potent estrogenic and antiestrogenic activity respectively. Antagonistic effects to AR were found in 7 compounds, with cyfluthrin and deltamethrin exhibiting stronger AR antagonistic capacity. In the TR assay, all of tested chemicals except DCCA showed antagonistic effects. In this study, we provided evidence that a variety of pyrethroids and their metabolites might disrupt the function of multiple nuclear hormone receptors and thus have the potentials to affect the endocrine and the reproductive systems in humans.

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These results suggest that different variants in the EPPIN gene may have different relationships with idiopathic male infertility and men carrying these variants have a decreased or increased risk of abnormal semen parameters associated with male infertility.

Objective: To assess whether single nucleotide polymorphisms of HSD17B5 (AKR1C3) (rs1937845 and rs12529) and HSD17B6 (rs898611) are associated with polycystic ovary syndrome (PCOS) in a Chinese population. Design: A case-control study was conducted to investigate the relation between HSD17B5 and HSD17B6 polymorphisms and PCOS. Methods: In this study, 335 patients with PCOS and 354 controls were recruited. The genotypes of HSD17B5 (rs1937845 and rs12529) and HSD17B6 (rs898611) were detected by the TaqMan method. Results and conclusions: We found that the genotypic frequencies of the rs1937845 polymorphism were different in subjects with PCOS compared with control, with the CT genotype being more commonly found in patients with PCOS than in controls (PZ0.005). We observed a significantly 1.74-fold higher risk of CT genotype in the polymorphism rs1937845 in women with PCOS vs the control group (adjusted odds ratio (OR), 1.74; 95% CIZ1.19-2.54; PZ0.005). A similar, significant 1.47-fold higher risk (adjusted OR, 1.47; 95% CIZ1.07-2.03; PZ0.018) was demonstrated for T allele of polymorphism rs1937845 associated with PCOS. In patients with PCOS, the rs12529 (GOC) and rs1937845 (COT) polymorphisms were strongly associated with the high level of testosterone. The TT carriers of polymorphism rs1937845 had a significantly increased homeostatic model assessment-B% (HOMA-B%) (PZ0.045) and that might be associated with the high risk of insulin resistance. However, no significant difference was found in genotype or allele distributions of the polymorphisms rs12529 of HSD17B5 and rs898611 of HSD17B6 between patients with PCOS and controls. Additionally, the two polymorphisms of HSD17B5 are associated with hyperandrogenemia in patients with PCOS. In conclusion, our findings showed a significant statistical association between HSD17B5 rs1937845 and PCOS risk in Chinese women. The CT genotype and T allele frequency are influenced significantly to a higher extent in patients with PCOS than controls. Further studies are needed to confirm the results and find out the exact molecular mechanism of the polymorphism on the risk of hyperandrogenemia and PCOS.

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