RESUMO
Fenvalerate is a synthetic pyrethroid insecticide used in agriculture and domestic insect control. Some studies have proposed that it may act as an environmental estrogen; other studies suggest possible genotoxicity in germ cells. This study aimed to evaluate the effects of fenvalerate on the female reproduction in rats whose mothers were exposed during gestation and lactation. Pregnant Wistar rats were exposed to fenvalerate (40 mg/kg) or corn oil (vehicle) orally from gestational day 12 until the end of lactation. The dose selection was based on previous studies, whereas this was considered an effective dose. Results showed decreases in ovarian weight, pre-antral follicles and corpora lutea at PND 75 and an increase in the resorption number, when fertility test was performed at PND 80. Under some experimental conditions, fenvalerate may impair reproductive development of female offspring, manifested as reduced fecundity and ovulation number, resulting from the impairment in corpora lutea counting.
Assuntos
Fertilidade/efeitos dos fármacos , Inseticidas/toxicidade , Nitrilas/toxicidade , Ovário/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal , Piretrinas/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Perda do Embrião/induzido quimicamente , Feminino , Lactação , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ovário/patologia , Ovulação/efeitos dos fármacos , Gravidez , Ratos , Ratos WistarRESUMO
BACKGROUND: Recent studies have supported the concept of "fetal programming" which suggests that during the intrauterine development the fetus may be programmed to develop diseases in adulthood. The possible effects of in utero protein restriction on sexual development of rat male offspring were evaluated in the present study. METHODS: Pregnant Wistar rats were divided into two experimental groups: one group treated with standard chow (SC, n = 8, 17% protein) and the other group treated with hypoproteic chow (HC, n = 10, 6% protein) throughout gestation. After gestation the two experimental groups received standard chow. To evaluate the possible late reproductive effects of in utero protein restriction, the male offspring of both groups were assessed at different phases of sexual development: prepubertal (30 days old); peripubertal (60 days old); adult (90 days old). Student's t-test and Mann-Whitney test were utilized. Differences were considered significant when p < 0.05. RESULTS: We found that in utero protein restriction reduced the body weight of male pups on the first postnatal day and during the different sexual development phases (prepubertal, peripubertal and adult). During adulthood, Sertoli cell number, sperm motility and sperm counts in the testis and epididymal cauda were also reduced in HC. Furthermore, the numbers of sperm presenting morphological abnormalities and cytoplasmic drop retention were higher in HC. CONCLUSIONS: In conclusion, in utero protein restriction, under these experimental conditions, causes growth delay and alters male reproductive-system programming in rats, suggesting impairment of sperm quality in adulthood.
Assuntos
Desenvolvimento Fetal , Complicações na Gravidez/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/metabolismo , Deficiência de Proteína/fisiopatologia , Desenvolvimento Sexual/fisiologia , Animais , Feminino , Masculino , Gravidez , Ratos , Ratos Wistar , Túbulos Seminíferos/crescimento & desenvolvimento , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Testosterona/sangueRESUMO
The aim of this study was to determine the consequent reproductive developmental and immunotoxic effects due to exposure to fenvalerate during pregnancy and lactation in male offspring of maternal-treated rats. Pregnant rats were treated daily by oral gavage with 40 or 80 mg/kg of fenvalerate or corn oil (vehicle, control), from d 12 of pregnancy to d 21 of lactation. Immune and reproductive developmental effects were assessed in male offspring at postnatal days (PND) 40 (peripuberty), 60 (postpuberty), and 90 (sexual maturity). Treatment with the higher dose (80 mg/kg) resulted in convulsive behavior, hyperexcitability, and mortality in 45% of the dams. Fenvalerate was detected in the fetus due to placental transfer, as well as in pups due to breast-milk ingestion, persisting in male offspring until PND 40 even though pesticide treatment was terminated on PND 20. However, fenvalerate did not produce marked alterations in age of testicular descent to the scrotum and prepucial separation, parameters indicative of puberty initiation. In contrast, at puberty, there was a reduction in testicular weight and sperm production in male offspring of maternal-treated rats. At adulthood, the sperm counts and fertility did not differ between control and treated groups. Testosterone levels were not changed at any time during reproductive development. Similarly, no apparent exposure-related effects were detected in the histological structures of the lymphohematopoietic system. Data indicate that fenvalerate, in this experimental model, interfered with initial development of the male reproductive system, but that these effects on sperm production or fertility did not persist into adulthood. There was no apparent evidence that fenvalerate altered testosterone levels or produced a disruption in male endocrine functions.
Assuntos
Tecido Linfoide/efeitos dos fármacos , Exposição Materna , Leite/química , Nitrilas/toxicidade , Praguicidas/toxicidade , Piretrinas/toxicidade , Testículo/efeitos dos fármacos , Animais , Animais Lactentes/crescimento & desenvolvimento , Medula Óssea/efeitos dos fármacos , Feminino , Infertilidade Masculina/induzido quimicamente , Masculino , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Ratos , Ratos Wistar , Testículo/crescimento & desenvolvimento , Testosterona/sangueRESUMO
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.