RESUMO
Phthalates, such as di-n-butyl phthalate (DBP) and di-isopentyl phthalate (DiPeP), are pollutants with a high potential for endocrine disruption. This study aimed to evaluate parameters of endocrine disruption in specimens of the Neotropical fish Rhamdia quelen exposed to DBP and DiPeP through their food. After 30 days of exposure, the fish were anesthetized and then euthanized, and blood, hypothalamus, liver, and gonads were collected. DBP caused statistically significant alterations in the serotoninergic system of males (5 and 25 ng/g) and females (5 ng/g) of R. quelen and it increased testosterone levels in females (25 ng/g). DiPeP significantly altered the dopaminergic system in females, reduced plasma estradiol levels (125 ng/g) and hepatic vitellogenin expression (25 ng/g), and changed the antioxidant system in gonads (125 ng/g). The results suggest that DBP and DiPeP may have different response patterns in females, with the former being androgenic and the latter being anti-estrogenic. These findings provide additional evidence regarding the molecular events involving DBP and DiPeP in the endocrine disruption potential in juvenile specimens of Rhamdia quelen.
Assuntos
Antioxidantes , Peixes-Gato , Dibutilftalato , Disruptores Endócrinos , Neurotransmissores , Vitelogeninas , Animais , Vitelogeninas/metabolismo , Vitelogeninas/sangue , Dibutilftalato/toxicidade , Disruptores Endócrinos/toxicidade , Feminino , Antioxidantes/metabolismo , Masculino , Neurotransmissores/metabolismo , Poluentes Químicos da Água/toxicidade , Ácidos Ftálicos/toxicidade , Gônadas/efeitos dos fármacosRESUMO
This rodent (Wistar rats) study examined reproductive effects of in utero/lactational exposure to a mixture of 6 antiandrogenic phthalates (PMix): diisobutyl phthalate, di-n-butyl phthalate, diisopentyl phthalate, butylbenzyl phthalate, di-2-ethylhexyl phthalate, and diisononyl phthalate. The PMix was defined based on exposure data from pregnant women in Brazil. Experimental groups were established by extrapolating the estimated human dose to rats (0.1 mg/kg/day), followed by up to 3 additional doses corresponding to 5, 1000, and 5000 times the starting rat dose: 0 (control), 0.1, 0.5, 100, and 500 mg/kg/day. The fetal experiment assessed gestational exposure effects on fetal gonads, whereas the postnatal experiment evaluated reproductive parameters in males and females after in utero and lactational exposure. Prenatal exposure decreased fetal testicular testosterone production at 0.5 and 500 mg/kg/day. PMix 500 also reduced mRNA expression of steroidogenesis-related genes, upregulated transcript expression of the retinoic acid-degrading enzyme Cyp26b1, and increased multinucleated gonocytes incidence in fetal testes. Postnatal assessment revealed antiandrogenic effects at the highest dose, including reduced anogenital distance, nipple retention, and decreased weight of reproductive organs. Early puberty onset (preputial separation) was observed at the lowest dose in males. In contrast, females did not show significant changes in fetal and adult endpoints. Overall, the PMix recapitulated early and late male rat phthalate syndrome phenotypes at the highest dose, but also induced some subtle changes at lower doses, which warrant confirmation and mechanistic assessments. Our data support the use of epidemiologically defined mixtures for exposure risk assessments over traditional toxicological approaches.
Assuntos
Dietilexilftalato , Ácidos Ftálicos , Efeitos Tardios da Exposição Pré-Natal , Humanos , Adulto , Ratos , Gravidez , Masculino , Feminino , Animais , Ratos Wistar , Ácidos Ftálicos/toxicidade , Ácidos Ftálicos/metabolismo , Reprodução , Testosterona/metabolismo , Testículo , Dietilexilftalato/toxicidade , Dibutilftalato/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/metabolismoRESUMO
This study investigated the acute effects of dibutyl phthalate (DBP) exposure on energy metabolism and gill histology in zebrafish (Danio rerio). The in vitro incubation of gill tissue with 10 µM DBP for 60 min altered tissue energy supply, as shown by decreased lactate content and lactate dehydrogenase (LDH) activity. Higher concentrations of DBP (100 µM and 1 mM) increased lactate content and LDH activity; however, they blocked glucose uptake, depleted the glycogen content in cellular stores, and induced injury to the gills, as measured by LDH release to the extracellular medium. In addition, in vivo exposure of fish to 1 pM DBP for 12 h induced liver damage by increasing alanine aminotransferase (ALT) and gamma-glutamyl transferase (GGT) activities. Gill histology indicated hyperemia, lamellar fusion, lamellar telangiectasis, and necrosis. Data indicate that acute exposure of zebrafish gills to the higher DBP concentrations studied induces anaerobic cellular activity and high lactate production, causing gill damage, diminishing cell viability, and incurring liver dysfunction.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Peixe-Zebra , Animais , Peixe-Zebra/metabolismo , Dibutilftalato/toxicidade , Dibutilftalato/metabolismo , Brânquias/metabolismo , Metabolismo Energético , Lactatos/metabolismo , Lactatos/farmacologiaRESUMO
Phthalic acid esters (PAEs) were determined in polyethylene covers used in horticultural production units located at Moreno and La Plata districts (Buenos Aires, Argentina), detecting 0.69-8.75 mg PAEs kg-1 plastic in greenhouse and tunnel films. The PAEs found were diisobutylphthalate (DIBP), dibutylphthalate (DBP) and diethylhexylphthalate (DEHP). DBP was chosen as a model molecule to carry out the photochemical degradation studies that led to the formation of monobutylphthalate (MBP) and phthalic acid (PA). DBP, MBP and PA migration from plastic covers was studied, finding that while DBP and MBP moved to soil and atmosphere in short times (<48 h), PA remained in the agricultural covers. Further experiments with DBP were made to explore the effect on migration of temperature (20 °C, 50 °C), film thickness (25 µm, 100 µm) and plastic ageing by solarization, observing that temperature increase, film thickness reduction and ageing by solarization favored DBP migration to the environment. DBP and MBP impact on soil were evaluated by avoidance and reproduction tests using Eisenia andrei as bioindicator. Both compounds reduced cocoon viability decreasing the number of juveniles at the lowest concentration assayed (0.1 mg kg-1 of soil). At higher DBP and MBP concentrations the reproductive parameters (number of total cocoons, hatchability and number of juveniles) also showed alterations compared with the controls. Carboxylesterases (CaE), cholinesterases (ChE) and glutathion-S-transferases (GST) activities were analyzed in E. andrei exposed to DBP; cholinesterases activities were reduced at 1 and 10 mg DBP kg-1 soil, and glutathione S-transferases activities were increased at 10 mg DBP kg-1 soil while no effect was observed on carboxylesterases activities. These results emphasize the need to continue studying the impact of PAEs and their photodegradation products on the environment.
Assuntos
Ácidos Ftálicos , Poluentes do Solo , China , Dibutilftalato/toxicidade , Ésteres , Fotólise , Ácidos Ftálicos/toxicidade , Plásticos , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidadeRESUMO
This study investigates the impacts of exposure to an environment Ca2+ challenge and the mechanism of action of dibutyl phthalate (DBP) on Ca2+ influx in the gills of Danio rerio. In vitro profile of 45Ca2+ influx in gills was verified through the basal time-course. Fish were exposed to low, normal and high Ca2+ concentrations (0.02, 0.7 and 2 mM) for 12 h. So, gills were morphologically analysed and ex vivo45Ca2+ influx at 30 and 60 min was determined. For the in vitro studies, gills were treated for 60 min with DBP (1 pM, 1 nM and 1 µM) with/without blockers/activators of ionic channels, Ca2+ chelator, inhibitors of ATPases, ionic exchangers and protein kinase C to study the mechanism of DBP-induced 45Ca2+ influx. Exposure to high environmental Ca2+ augmented 45Ca2+ influx when compared to fish exposed to normal and low Ca2+ concentrations. Additionally, histopathological changes were observed in the gills of fish maintained for 12 h in low and high Ca2+. In vitro exposure of gills to DBP (1 pM) disturbed Ca2+ homeostasis. DBP stimulated 45Ca2+ influx in gills through the transitory receptor potential vanilloid 1 (TRPV1), and reverse-mode Na+/Ca2+ exchanger (NCX) activation, protein kinase C and K+ channels and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). These data suggest that in vivo short-term exposure of gills to low and high Ca2+ leads to 45Ca2+ influx and histopathological changes. Additionally, the DBP-induced rapid 45Ca2+ influx is mediated by TRPV1, NCX activation with the involvement of PKC, K+-channels and SERCA, thereby altering Ca2+ homeostasis.
Assuntos
Radioisótopos de Cálcio/metabolismo , Cálcio/metabolismo , Dibutilftalato/toxicidade , Brânquias/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra/metabolismo , Animais , Cálcio/toxicidade , Dibutilftalato/metabolismo , Retículo Endoplasmático/metabolismo , Brânquias/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Canais de Cátion TRPV/metabolismo , Poluentes Químicos da Água/metabolismoRESUMO
The increased incidence of testicular disorders in young men and the possible influence of environmental chemicals, such as dibutyl phthalate (DBP) and acrylamide (AA), requires experimental models for identifying modes of action. Most published reproductive toxicologic studies use RNA samples from the total testis to evaluate testicular gene expression; however, analyses of isolated cell types could provide a more specific tool. Among testicular germ cells, spermatogonia are critical since they represent the onset of spermatogenesis. This study aimed, (1) to establish a technique for spermatogonia isolation; (2) to apply this isolation technique to verify possible gene expression alterations (Pou5f1, Kitlg, Mki-67, Bak1 and Spry4) in prepubertal post-natal day, (PND24) and pubertal (PND45) testes after in utero and postnatal exposure to DBP or AA. The technique was efficient for isolation of a majority of spermatogonia. In utero DBP exposure led to reduced litter body weight at birth, reduced anogenital distance of male pups on PND4, and increased frequency of male nipple retention on PND14 compared to controls. DBP-exposed relative testes weights were reduced only at PND24 compared to control but they did not differ at PND45. DBP-exposed animals showed reduced expression levels of Pou5f1 and Mki67 on PND24, and reduced expression of Pou5f1 and Spry4 on PND45. AA exposure reduced expression of Pou5f1, Mki67, and Spry4 at PND45 although not significantly. Our results suggest that DBP acts by reducing cell proliferation and impairing differentiation in prepubertal and pubertal testes.
Assuntos
Acrilamida/toxicidade , Dibutilftalato/toxicidade , Poluentes Ambientais/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Espermatogônias/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Peso Corporal , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Feminino , Expressão Gênica/efeitos dos fármacos , Masculino , Tamanho do Órgão/efeitos dos fármacos , Gravidez , Efeitos Tardios da Exposição Pré-Natal/genética , Efeitos Tardios da Exposição Pré-Natal/patologia , Ratos Sprague-Dawley , Espermatogônias/patologia , Testículo/embriologia , Testículo/crescimento & desenvolvimento , Testículo/patologiaRESUMO
Cryptorchidism (CPT), the most common male congenital abnormality, is variably associated with other male reproductive tract problems. We evaluated if cryptorchid rats develop enhanced testicular susceptibility to dibutyl phthalate (DBP) or acrylamide (AA) after extended exposure. Three studies with rats were performed: (1) in utero and postnatal exposure to DBP or AA; (2) establishment of CPT and orchiopexy; and (3) in utero and postnatal exposures to DBP or AA associated with CPT/orchiopexy. Seminiferous tubules were histologically scored according to the severity of lesions: (1) Rats exposed to DBP (score 1.5) or AA (score 1.1) presented mostly preserved spermatogenesis. Some seminiferous tubules showed vacuolated germinative epithelium, germ cell apoptosis, and a Sertoli cell-only (SCO) pattern. (2) CPT (score 3.3) resulted in decreased absolute testes weights, degenerated and SCO tubules, and spermatogenesis arrest that were reversed by orchiopexy (score 1.1). (3) Exposure to DBP or AA with CPT/orchiopexy led to atrophic testes, spermatogenesis arrest, germ cell exfoliation/multinucleation, and SCO tubules (both chemicals score 2.5). Exposure to chemicals such as DBP or AA prevented the recovery of cryptorchid testes by orchiopexy. The possible role of environmental contaminants should be considered when looking for factors that modulate human testicular disorders associated with CPT.
Assuntos
Acrilamida/toxicidade , Criptorquidismo/cirurgia , Dibutilftalato/toxicidade , Testículo/efeitos dos fármacos , Animais , Criptorquidismo/patologia , Modelos Animais de Doenças , Feminino , Masculino , Troca Materno-Fetal , Orquidopexia , Gravidez , Ratos Sprague-Dawley , Testículo/patologiaRESUMO
Prenatal exposure to phthalates is associated with reproductive and metabolic systems alterations. We investigated the effects of in utero and lactational exposure to Di-(2-ethyl-hexyl) phthalate (DEHP) and Di-n-butyl phthalate (DBP) on the reproductive system and glycemic homeostasis in male and female offspring of rats. Pregnant rats were exposed to equimolar doses (0.018, 0.18 and 1.8 mmol/kg/day) of DEHP or DBP corresponding to 7, 70, and 700 mg/kg/day for DEHP and 5, 50, and 500 mg/kg/day for DBP, respectively, by oral gavage from gestation day 13 to postnatal day 21, and using canola oil as vehicle control. Male and female offspring were examined for body weight development, external markers of prenatal androgenization and puberty onset, plasma concentrations of glucose and insulin, insulin tolerance (ITT), glucose-stimulated insulin secretion (GSIS), and the expression of peroxisome proliferator-activated receptor gamma (PPARγ) and pancreatic and duodenal homeobox 1 protein (PDX-1). Male and female rats exposed to the highest doses of DEHP and DBP exhibited increased fasting glucose levels. In rats exposed to DEHP 700 mg/kg/day we also observed a reduced glucose decay rate (Kitt) following insulin administration and decreased insulin secretion in the GSIS assay. Male offspring exposed to DEHP 700 mg/kg/day had reduced anogenital distance (AGD) on PDN 4 and delayed preputial separation at puberty, while female offspring exposed to DEHP 70 and 700 mg/kg/day and to the highest DBP dose had delayed vaginal opening. Our results suggest that maternal treatment with DEHP and DBP can induce a wide range of metabolic and reproductive alterations in offspring rats, with more pronounced effects following DEHP exposure.
Assuntos
Glicemia/efeitos dos fármacos , Dibutilftalato/toxicidade , Dietilexilftalato/toxicidade , Genitália/efeitos dos fármacos , Troca Materno-Fetal , Plastificantes/toxicidade , Canal Anal/anatomia & histologia , Animais , Feminino , Genitália/anatomia & histologia , Genitália/crescimento & desenvolvimento , Homeostase/efeitos dos fármacos , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos WistarRESUMO
In the present study, it was evaluated the susceptibility of prostatic lesions in male adult rats exposed to Di-N-butyl-phthalate during fetal and lactational periods and submitted to MNU plus testosterone carcinogenesis protocol. Pregnant females were distributed into four experimental groups: CN (negative control); CMNU (MNU control); TDBP100 (100 mg/kg of DBP); TDBP500 (500 mg/kg of DBP). Females from the TDBP groups received DBP, by gavage, from gestation day 15 (GD15) to postnatal day 21 (DPN21), while C animals received the vehicle (corn oil). CMNU, TDBP100, and TDBP500 groups received a single intraperitoneal injection of MNU (50 mg/kg) on the sixth postnatal week. After that, testosterone cypionate was administered subcutaneously two times a week (2 mg/kg) for 24 weeks. The animals were euthanized on PND220. Distal segment fragments of the ventral (VP) and dorsolateral prostate (DLP) were fixed and processed for histopathological analysis. Protein extracts from ventral prostate were obtained, and western blotting was performed to AR, ERα, MAPK (ERK1/2), and pan-AKT. Stereological analysis showed an increase in the epithelial compartment in TDBP100 and TDBP500 compared to CN. In general, there was increase in the incidence of inflammation and metaplasia/dysplasia in the DBP-treated groups, mainly in DLP, compared to CN and CMNU. Proliferation index was significant higher in TDBP500 and PIN (prostatic intraepithelial neoplasia) was more frequent in this group compared to CMNU. Western blot assays showed an increase in the expressions of AR and MAPK (ERK1/2) in the TDBP100 compared to CN, and ERα and AKT expressions were higher in the TDBP500 group compared do CN. These results showed that different doses of DBP during prostate organogenesis in Wistar rats could increase the incidence of premalignant lesions in initiated rats inducing distinct biological responses in the adulthood. © 2015 Wiley Periodicals, Inc. Environ Toxicol 31: 1185-1195, 2016.
Assuntos
Dibutilftalato/toxicidade , Metilnitrosoureia/toxicidade , Próstata/efeitos dos fármacos , Testosterona/análogos & derivados , Animais , Western Blotting , Receptor alfa de Estrogênio/metabolismo , Feminino , Inflamação/etiologia , Inflamação/metabolismo , Lactação , Masculino , Exposição Materna , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Gravidez , Próstata/metabolismo , Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Receptores Androgênicos/metabolismo , Testosterona/sangue , Testosterona/toxicidade , Regulação para Cima/efeitos dos fármacosRESUMO
Lightsticks are artifacts used as attractors in a type of commercial fishery, known as surface longline gear. Despite the excessive use, the contamination risks of these devices have not yet been properly investigated. This research aimed to fill up this gap by determining the chemical composition and the toxicity of lightsticks recently activated, compared to those one year after activation and to the ones collected on the beaches. The analyzes were carried out by Gas Chromatography coupled with Mass Spectrometry (GC-MS). Additionally, the variations in composition and the toxicity of their sea Water Soluble Fractions (WSF) were evaluated based on the WSF-effects of Crassostrea rhizophorae embryonic development. The GC-MS analysis made possible the identification of nineteen substances in the water soluble fraction of the lightsticks, such as dibutyl phthalate (DBP) and dimethyl phthalate (DMP). The value of the WSF-effective concentration (EC50) was in an average of 0.35%. After one year of the lightsticks activation, the toxicity was even higher (0.65%). Furthermore, other substances, also present in the lightsticks-WSF caused persistent toxicity even more dangerous to the environment than DBP and DMP. This essay discusses their toxicity effects and possible environment damages.
Assuntos
Crassostrea/embriologia , Desenvolvimento Embrionário/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Animais , Dibutilftalato/toxicidade , Cromatografia Gasosa-Espectrometria de Massas , Ácidos Ftálicos/toxicidadeRESUMO
It has been hypothesized that oils containing high levels of omega-3 polyunsaturated fatty acids, such as canola and fish oil, could counteract some of the adverse effects induced by phthalates. In the present study, the influence of different oily vehicles on di-butyl phthalate (DBP)-induced testicular toxicity and lipid profile was investigated. Pregnant Wistar rats were treated by oral gavage from gestation days 13 to 20 with DBP (500 mg/kg/day) diluted in three different vehicles: corn, canola or fish oil. Male fetuses were analyzed on gestation day 20. DBP exposure lowered intratesticular testosterone levels and anogenital distance, regardless of the vehicle used. The percentage of seminiferous cords containing multinucleated gonocytes and cord diameter was increased in DBP-exposed groups, compared with vehicle controls, with no difference between the three DBP-exposed groups. Clustering of Leydig cells was seen in all DBP groups. Lipid profile indicated that administration of canola and fish oil can increase the content of omega-3 fatty acids in rat testis. However, content of omega-3 was diminished in DBP-treated groups. Overall, our results indicate that different oily vehicles did not alter fetal rat testicular toxicity induced by a high DBP dose.
Assuntos
Dibutilftalato/toxicidade , Disruptores Endócrinos/toxicidade , Ácidos Graxos Ômega-3/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Exposição Materna/efeitos adversos , Veículos Farmacêuticos/metabolismo , Testículo/efeitos dos fármacos , Animais , Óleo de Milho/química , Óleo de Milho/metabolismo , Dibutilftalato/administração & dosagem , Disruptores Endócrinos/administração & dosagem , Poluentes Ambientais/administração & dosagem , Poluentes Ambientais/toxicidade , Ácidos Graxos Monoinsaturados/química , Ácidos Graxos Monoinsaturados/metabolismo , Ácidos Graxos Ômega-3/química , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Óleos de Peixe/química , Óleos de Peixe/metabolismo , Masculino , Veículos Farmacêuticos/química , Plastificantes/administração & dosagem , Plastificantes/toxicidade , Gravidez , Óleo de Brassica napus , Ratos , Processos de Determinação Sexual/efeitos dos fármacos , Testículo/embriologia , Testículo/metabolismo , Testosterona/metabolismoRESUMO
OBJECTIVES: The aim of this study was to evaluate the cytotoxic effect of the monomers isobutyl methacrylate (IBMA) and 1,6-hexanediol dimethacrylate (1,6-HDMA), the plasticizer di-n-butyl phthalate (DBP), and the degradation by-products methacrylic acid (MA) and benzoic acid (BA) on L929 cells. Based on previous investigations on the release of these compounds from hard chairside reline resins, a range of concentrations (micromol/L) were selected for the cytotoxicity tests (IBMA, 5.49-1406.57; 1,6-HDMA, 1.22-39.32; DBP, 1.12-143.8; MA, 9.07-581; BA, 3.19-409). METHODS: Cytotoxic effects were assessed using MTT and (3)H-thymidine assays after the cells had been exposed to the test compounds at the given concentrations for 24 h. Cytotoxicity was rated based on cell viability relative to controls (cells exposed to medium without test substances). RESULTS: DNA synthesis activity was inhibited by all compounds. Mitochondrial dehydrogenase activity decreased in cells treated with monomers, plasticizer and MA by-product, whereas no cytotoxic effect was observed on contact with BA at the majority of concentrations tested. The ranges of suppression for (3)H-thymidine assay were: IBMA, 25-95%; 1,6-HDMA, 95-98%; DBP, 40-98%; MA, 97-99%; BA, 54-71%. For MTT assay, the ranges of suppression were: IBMA, 0-96%; 1,6-HDMA, 26-89%; DBP, 17-80%; MA, 52-66%; BA, 0-27%. The (3)H-thymidine assay was more sensitive than the MTT assay. SIGNIFICANCE: This study evaluated the cytotoxicity of a wide range of concentrations of monomers (IBMA and 1,6-HDMA), plasticizer (DBP) and degradation by-products (MA and BA), including those expected to be released from hard chairside reline resins. The differences observed in the cytotoxicity of these compounds, along with other properties, may assist the dental practitioners in the selection of reline materials with improved service life performance and low risk of adverse reactions in patients who wear relined dentures.
Assuntos
Ácido Benzoico/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Reembasadores de Dentadura/efeitos adversos , Metacrilatos/toxicidade , Plastificantes/toxicidade , Animais , Proliferação de Células/efeitos dos fármacos , Dano ao DNA , Reembasamento de Dentadura/efeitos adversos , Dibutilftalato/toxicidade , Relação Dose-Resposta a Droga , Fibroblastos/efeitos dos fármacos , Células L , Camundongos , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Inibidores da Síntese de Ácido Nucleico , Sais de Tetrazólio/metabolismo , Timidina/metabolismoRESUMO
The potential adverse reproductive effects, with emphasis on the epididymis, of in utero and lactational exposure to 100 mg/kg/d di-n-butyl phthalate (DBP) in adult male rat offspring were investigated. The fetal testis histopathology was also determined. The selected endpoints included reproductive organ weights, sperm motility and morphology, sperm epididymal transit time, sperm quantity in the testis and epididymis, hormonal status, fetal testis and epididymal histopathology and stereology, and androgen receptor (AR), aquaporin 9 (AQP9), and Ki-67 immunoreactivities. Pregnant females were divided into two groups: control (C) and treated (T). The treated females received DBP (100 mg/kg/d, by gavage) from gestation day (GD) 12 to postnatal day (PND) 21, while control dams received the vehicle. Some pregnant dams were killed by decapitation on GD20, and testes from male fetuses were collected for histopathogy. Male rats from other dams were killed at PND 90. Fetal testes from treated group showed Leydig-cell clusters, presence of multinucleated germinative cells, and increase of the interstitial component. Testosterone levels and reproductive organ weights were similar between the treated and control adult groups. DBP treatment did not markedly affect relative proportions of epithelial, stromal, or luminal compartments in the epididymis; sperm counts in the testis and epididymis; sperm transit time; or sperm morphology and motility in adult rats. The AR and AQP9 immunoreactivities and proliferation index were similar for the two groups. These results showed that fetal testes were affected by DBP as evidenced by testicular histopathologic alterations, but reproductive parameters and epididymal structure/function were not significantly altered in the adult animals exposed to 100 mg/kg DBP in utero and during lactation.
Assuntos
Dibutilftalato/toxicidade , Desenvolvimento Fetal/efeitos dos fármacos , Exposição Materna , Plastificantes/toxicidade , Testículo/efeitos dos fármacos , Animais , Animais Lactentes/crescimento & desenvolvimento , Feminino , Infertilidade Masculina/induzido quimicamente , Masculino , Gravidez , Ratos , Ratos Wistar , Motilidade dos Espermatozoides/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testosterona/sangueRESUMO
Phthalates are environmental contaminants used in the production of plastics, cosmetics and medical devices. Studies on the effects of phthalates on female reproductive health are particularly sparse and mostly restricted to high-dose exposure in rats. In the present study, pregnant rats were treated with 100mg/kg-d of di-eta-butyl-phthalate (DBP) or only the vehicle (control group), from GD 12 to GD 20 for evaluation of reproductive outcomes and fetal gonads analysis (F0), and from GD 12 to PND 21 to evaluate reproductive development and function on F1 female offspring. Results showed that all parameters were comparable between groups, although there was a significant increase in the fetal weight after DBP exposure. However, the body weight at birth was normal. Based on these data we can conclude that, in these experimental conditions, DBP did not disturb the reproductive development or function of female rats.
Assuntos
Dibutilftalato/toxicidade , Lactação , Plastificantes/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Reprodução/efeitos dos fármacos , Reprodução/fisiologia , Animais , Peso ao Nascer/efeitos dos fármacos , Dibutilftalato/administração & dosagem , Feminino , Fertilidade/efeitos dos fármacos , Peso Fetal/efeitos dos fármacos , Masculino , Ovário/efeitos dos fármacos , Ovário/embriologia , Plastificantes/administração & dosagem , Gravidez , Ratos , Ratos Wistar , Maturidade Sexual/efeitos dos fármacosRESUMO
In the present study we evaluated the toxic effects on the male adult rat prostate of DBP exposure during fetal and lactational periods, because although many studies have addressed the influence of phthalates on the male reproductive system, only a few have discussed their possible effects on prostate development. Pregnant females were distributed into two experimental groups: Control (C) and Treated (T). The females of the T group received DBP (100mg/kg, by gavage) from gestation day 12 to postnatal day 21, while C rats received the vehicle (corn oil). In adulthood (90 days old), the animals were euthanized. The serum and testicular testosterone levels were measured. Ventral prostate was removed and weighed. Distal segment fragments of the ventral prostate were fixed and processed for histochemistry and immunohistochemistry to detect androgen receptor (AR) and Ki67 antigens. Protein extraction from ventral prostate fragments was performed for AR immunoblotting and Gelatin zymography for MMP-2 and MMP-9 (MMP, metalloproteinase). Stereological and histopathological analyses were also performed. Serum and testicular testosterone levels and prostate weight were comparable between groups. In the T group the relative proportions (%) of epithelial (C=32.86; T=42.04*) and stromal (C=21.61; T=27.88*) compartments were increased, while the luminal compartment was decreased (C=45.54; T=30.08*), *p<0.05. InT, disseminated inflammatory infiltrate in the stroma, associated or not with epithelial dysplasia and PIN (Prostatic Intraepithelial Neoplasia), was observed. Increases in AR expression, proliferation index and metalloproteinase 9 (MMP-9) activity were noted in T animals. In some T animals, collagen fibrils accumulated adjacent to the epithelium. As far as we are aware, this is the first report in the literature showing that phthalates could play a role in proliferative and inflammatory disorders of the rat prostate.