Quantification of the uptake and elimination of nanomaterials (NMs) by organisms is key in assessing the environmental risks of NMs.

Antenatal betamethasone is used for accelerating fetal lung maturation for women at risk of preterm birth. Altered sperm parameters were reported in adult rats after intrauterine exposure to betamethasone. In this study, male rat offspring were assessed for reproductive development after dam exposure to betamethasone (0.1mg/kg) or vehicle on Days 12, 13, 18 and 19 of pregnancy. The treatment resulted in reduction in the offspring body weight, delay in preputial separation, decreased seminal vesicle weight, testosterone levels and fertility, and increased testicular weight. In the testis, morphologically abnormal seminiferous tubules were observed, characterized by an irregular cell distribution with Sertoli cell that were displaced towards the tubular lumen. These cells expressed both Connexin 43 (Cx43) and Proliferative Nuclear Cell Antigen (PCNA). In conclusion, intrauterine betamethasone treatment appears to promote reproductive programming and impairment of rat sexual development and fertility due to, at least in part, unusual testicular disorders.

Betamethasone is the drug of choice for antenatal treatment, promoting fetal lung maturation, decreasing the incidence of respiratory distress syndrome and neonatal mortality. Previous studies reported that prenatal treatment with this drug reduced testosterone levels, sperm quality and fertility in adult rats. We aimed to further evaluate the reproductive consequences of prenatal betamethasone exposure in male rats. Pregnant Wistar rats (n=13/group) were separated into two groups: control (vehicle) and betamethasone- treated (0.1mg/kg IM) and rats were injected on gestational days 12, 13, 18 and 19. Body weight, sexual behavior, reproductive organ weights, serum hormone levels, accessory glands contractility, sperm parameters, and fertility after in utero artificial insemination were evaluated. Our results showed that prenatal betamethasone exposure provoked a significant reduction in body weight at PND 01 and, at adulthood, decrease in FSH levels, sperm motility and production. Furthermore, seminal vesicle weight was decreased while testicular and ventral prostate weights were increased. Serum LH levels and the percentage of abnormal sperm were significantly increased. Although sexual behavior was not altered, a significant reduction in fertility in the adult rats exposed prenatally to betamethasone was noted. We concluded that prenatal betamethasone exposure leads to long-term reproductive impairment in male rats. These results may have important implications for humans, considering the use of this glucocorticoid in pregnant women.

Nanoparticle characteristics and exposure route greatly influence the toxicokinetics of pristine and (simulated) aged silver nanoparticles in Physa acuta.

Betamethasone is the drug of choice for antenatal treatment, promoting fetal lung maturation and decreasing mortality. Previous studies in rats reported male programming and alteration in sperm parameters and sexual behavior following intrauterine betamethasone exposure. The impact on the female reproductive development is not known. In this study, rat female offspring was assessed for sexual development, morphophysiology of the reproductive tract and fertility after maternal exposure to 0.1 mg kg of betamethasone or vehicle on gestational days 12, 13, 18 and 19. The treatment promoted reduction of litter weight on postnatal day 1, morphological masculinization in females, delay in the age of puberty onset, reduction in estrus number, increase in estrous cycle length and increase in luteinizing hormone serum levels and uterus weight. The females from the betamethasone group showed an increase of myometrial uterine area and decrease in endometrial uterine area. These animals also performed less lordosis during the sexual behavior test and showed impaired reproductive performance. The uterus showed higher contraction in the treated group as shown by a pharmacological assay. In conclusion, prenatal betamethasone exposure in rats promoted female masculinization, altered sexual development and reproductive parameters. Copyright © 2017 John Wiley & Sons, Ltd.

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The exposure to pesticides by nontarget soil biota has long been regarded as a serious downside of modern agricultural regimes and the subject of heated debate. Of utmost relevance is the exposure to pesticide mixtures because their effects have been shown to not necessarily reflect the individual toxicity of their components, and even the simple addition of effects may lead to consequences not clearly anticipated. In the present study, a multiple biomarker approach was employed to identify the mechanistic and time effects underlying several single and mixture treatments of chlorpyrifos (CPF) and mancozeb (MCZ) in juveniles and adults of the terrestrial isopod Porcellionides pruinosus. The effects of the individual pesticides and the mixtures at recommended doses were mostly transitory under these controlled conditions and one-pulse exposure. Whereas imbalances were identified on detoxification and oxidative stress-related enzymes, the isopods generally showed the ability to recover through the end of the experiment. However, juveniles displayed greater vulnerability than adults. Most of the differences between life stages occurred in energy-related parameters where distinct performances and stress-handling behaviors were observed, suggesting higher metabolic costs to juveniles. Our results stress that understanding the time dependence of the underlying mechanisms governing the joint effects of the pesticides can help in assessing and anticipating the effects of the pesticide mixtures. Moreover, we emphasize the importance of taking life stage-related differences into consideration when evaluating the environmental risks of pesticides and pesticide mixtures. Environ Toxicol Chem 2018;37:1446-1457. © 2018 SETAC.

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