933 resultados para ENDOCRINE DISRUPTION
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Pharmaceuticals and personal care products (PPCPs) are widely used on a daily basis. After their usage they reach the wastewater treatment plants (WWTPs). These compounds have different physico-chemical characteristics, which makes them difficult to completely remove in the WWTPs, througth conventional treatments. Currently, there is no legislation regarding PPCPs thresholds in effluent discharge. But, even at vestigial concentrations, these compounds enclose environmental risks due to, e.g., endocrine disruption potential. There is a need of alternative techniques for their removal in WWTPs. The main goal of this work was to assess the use of electrodialytic (ED) process to remove PPCPs from the effluent to be discharged. A two-compartment ED cell was used testing (i) the effluent position in the cell (anode and cathode compartment); (ii) the use of anion (AEM) and cation exchange membrane (CEM); (iii) the treatment period (6, 12 and 24 hours); (iv) effluent recirculation and current steps; (v) the feasibility of sequential treatments. Phosphorus (P) removal from effluent and energetic costs associated to the process were also evaluated. Five PPCPs were studied – caffeine (CAF), bisphenol A (BPA), 17 β-estradiol (E2), ethinyl estradiol (EE2) and oxybenzone (MBPh). The ED process showed to be effective in the removal when effluent is in the anode compartment. Oxidation is suggested to be the main removal process, which was between 88 and 96%, for all the compounds, in 6 hours. Nevertheless, the presence of intermediates and/or by-products was also observed in some cases. Effluent recirculation should have a retention time in the ED cell big enough to promote removal whereas the current steps (effluent in anode compartment) slightly increased removal efficiencies (higher than 80% for all PPCPs). The sequential set of ED treatment (effluent in anode compartment) showed to be effective during both periods with a removal percentage between 80 and 95% and 73 to 88% in the case of AEM and CEM, respectively. Again, the main removal process is strongly suggested to be oxidation in the anode compartment. However, there was an increase of BOD5 and COD, which might be explained by effluent spiking, these parameters limiting the effluent discharge. From these treatments, the use of AEM, enhanced the P removal from effluent to minimize risk of eutrophication. Energetic costs of the best set-up (6 hours) are approximately 0,8€/m3 of wastewater, a value considered low, attending to the prices of other treatment processes.
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As a consequence of its widespread use as an antimicrobial agent in consumer goods, triclosan has become distributed ubiquitously across the ecosystem, and recent reports that it can cause endocrine disruption in aquatic species has increased concern. It is reported here that triclosan possesses intrinsic oestrogenic and androgenic activity in a range of assays in vitro which could provide some explanation for the endocrine disrupting properties described in aquatic populations. In terms of oestrogenic activity, triclosan displaced [H-3]oestradiol from oestrogen receptors (ER) of MCF7 human breast cancer cells and from recombinant human ER alpha/ER beta. Triclosan at 10(-5) M completely inhibited the induction of the oestrogen-responsive ERE-CAT reporter gene in MCF7 cells by 10(-10) M 17 beta-oestradiol and the stimulation of growth of MCF7 human breast cancer cells by 10(-10) M 17 beta-oestradiol. On its own, 1 mu M triclosan increased the growth of MCF7 cells over 21 days. Triclosan also had androgenic activity. It displaced [H-3]testosterone from binding to the ligand binding domain of the rat androgen receptor (AR). Triclosan was able to inhibit the induction of the androgen-responsive LTR-CAT reporter gene in S115 mouse mammary tumour cells by 10(-9) M testosterone and in T47D human breast cancer cells by 10(-8) M testosterone at concentrations of 10(-7) M and 10(-6) M, respectively. Triclosan at 2 x 10(-5) M antagonized the stimulation of the growth of S115+A mouse mammary tumour cells by 10(-9) M testosterone. The finding that triclosan has oestrogenic and androgenic activity warrants further investigation in relation to both endocrine disruption of aquatic wildlife and any possible impact on human health. Copyright (C) 2007 John Wiley & Sons, Ltd.
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Phthalates are industrial additives widely used as plasticizers. In addition to deleterious effects on male genital development, population studies have documented correlations between phthalates exposure and impacts on reproductive tract development and on the metabolic syndrome in male adults. In this work we investigated potential mechanisms underlying the impact of DEHP on adult mouse liver in vivo. A parallel analysis of hepatic transcript and metabolic profiles from adult mice exposed to varying DEHP doses was performed. Hepatic genes modulated by DEHP are predominantly PPARalpha targets. However, the induction of prototypic cytochrome P450 genes strongly supports the activation of additional NR pathways, including Constitutive Androstane Receptor (CAR). Integration of transcriptomic and metabonomic profiles revealed a correlation between the impacts of DEHP on genes and metabolites related to heme synthesis and to the Rev-erbalpha pathway that senses endogenous heme level. We further confirmed the combined impact of DEHP on the hepatic expression of Alas1, a critical enzyme in heme synthesis and on the expression of Rev-erbalpha target genes involved in the cellular clock and in energy metabolism. This work shows that DEHP interferes with hepatic CAR and Rev-erbalpha pathways which are both involved in the control of metabolism. The identification of these new hepatic pathways targeted by DEHP could contribute to metabolic and endocrine disruption associated with phthalate exposure. Gene expression profiles performed on microdissected testis territories displayed a differential responsiveness to DEHP. Altogether, this suggests that impacts of DEHP on adult organs, including testis, could be documented and deserve further investigations.
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Energy balance is maintained by controlling both energy intake and energy expenditure. Thyroid hormones play a crucial role in regulating energy expenditure. Their levels are adjusted by a tight feed back-control led regulation of thyroid hormone production/incretion and by their hepatic metabolism. Thyroid hormone degradation has previously been shown to be enhanced by treatment with phenobarbital or other antiepileptic drugs due to a CAR-dependent induction of phase 11 enzymes of xenobiotic metabolism. We have recently shown, that PPAR alpha agonists synergize with phenobarbital to induce another prototypical CAR target gene, CYP2B1. Therefore, it was tested whether a PPAR alpha agonist could enhance the phenobarbital-dependent acceleration of thyroid hormone elimination. In primary cultures of rat hepatocytes the apparent half-life of T3 was reduced after induction with a combination of phenobarbital and the PPARa agonist WY14643 to a larger extent than after induction with either Compound alone. The synergistic reduction of the half-life could be attributed to a synergistic induction of CAR and the CAR target genes that code for enzymes and transporters involved in the hepatic elimination of T3, such as OATP1A1, OATP1A3, UGT1A3 and UCT1A10. The PPAR alpha-dependent CAR induction and the subsequent induction of T3-eliminating enzymes might be of physiological significance for the fasting-incluced reduction in energy expenditure by fatty acids as natural PPARa ligands. The synergism of the PPAR alpha agonist WY14643 and phenobarbital in inducing thyroid hormone breakdown might serve as a paradigm for the synergistic disruption of endocrine control by other combinations of xenobiotics. (C) 2009 Elsevier Inc. All rights reserved.
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This work was carried out to verify the effect of a glyphosate-based herbicide on Jundia hormones (cortisol, 17 beta-estradiol and testosterone), oocyte and swim-up fry production. Earthen ponds containing Jundia females were contaminated with glyphosate (3.6 mg/L); blood samples were collected from eight females from each treatment immediately before, or at 1, 10, 20 30 and 40 days following contamination. A typical post-stress rise in cortisol levels was observed at the 20th and 40th days following exposure to glyphosate. At the 40th day, 17 beta-estradiol was decreased in the exposed females. A similar number of oocytes were stripped out from females from both groups, however, a lower number of viable swim-up fry were obtained from the herbicide exposed females, which also had a higher liver-somatic index (LSI). The results indicate that the presence of glyphosate in water was deleterious to Rhamdia quelen reproduction, altering steroid profiles and egg viability. (c) 2006 Elsevier B.V. All rights reserved.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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We investigated the effects of an inhalatory anesthetic (ethyl ether) during the neonatal period of brain sexual differentiation on the later fertility and sexual behavior of male rats. Animals were exposed to ethyl ether immediately after birth. At adulthood, body weight, testes wet weight, and plasma testosterone levels were not affected; however, neonatal exposure to ether showed alterations on male fertility: a decrease in the number of spermatids and spermatozoa, an increase in the transit time of cauda epididymal spermatozoa and a decrease in daily sperm production. An alteration of sexual behavior was also observed: decreased male sexual behavior and appearance of homosexual behavior when the male rats were castrated and pretreated with exogenous estrogen. Probably, the ether delayed or reduced the testosterone peak of the sexual differentiation period, altering the processes of masculinization and defeminization of the hypothalamus. Our results indicate that perinatal exposure to ethyl ether during the critical period of male brain sexual differentiation, acting as endocrine disruptors, has a long-term effect on the fertility and sexual behavior of male rats, suggesting endocrine disruption through incomplete masculinization and defeminization of the central nervous system. © 2002 Elsevier B.V. All rights reserved.
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Exposure to agrichemicals can have deleterious effects on fish, such as disruption of the hypothalamus-pituitary-inter-renal axis (HPI) that could impair the ability of fish to respond to stressors. In this study, fingerlings of the teleost jundiá (Rhamdia quelen) were used to investigate the effects of the commonly used agrichemicals on the fish response to stress. Five common agrichemicals were tested: the fungicide - tebuconazole, the insecticide - methyl-parathion, and the herbicides - atrazine, atrazine + simazine, and glyphosate. Control fishes were not exposed to agrichemicals and standard stressors. In treatments 2-4, the fishes were exposed to sub-lethal concentrations (16.6%, 33.3%, and 50% of the LC50) of each agrichemical for 96 h, and at the end of this period, were subjected to an acute stress-handling stimulus by chasing them with a pen net. In treatments 5-7 (16.6%, 33.3%, and 50% of the LC50), the fishes were exposed to the same concentrations of the agrichemicals without stress stimulus. Treatment 8 consisted of jundiás not exposed to agrichemicals, but was subjected to an acute stress-handling stimulus. Jundiás exposed to methyl-parathion, atrazine + simazine, and glyphosate presented a decreased capacity in exhibiting an adequate response to cope with stress and in maintaining the homeostasis, with cortisol level lower than that in the control fish (P < 0.01). In conclusion, the results of this study clearly demonstrate that the acute exposure to sub-lethal concentrations of methyl-parathion, atrazine + simazine, and glyphosate exert a deleterious effect on the cortisol response to an additional acute stressor in the jundiá fingerlings. © 2008 Elsevier Inc. All rights reserved.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Química - IQ
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)