Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Environ Toxicol Pharmacol ; 63: 34-47, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30142495

RESUMO

Diesel exhaust emissions (DEE), being one of the main causes of ambient air pollution, exert a detrimental effect on human health and increase morbidity and mortality related to cardiovascular and pulmonary diseases. Therefore, the objective of the present study was to investigate potential adverse effects of exhausts emissions from B7 fuel, the first-generation biofuel containing 7% of fatty acid methyl esters (FAME), and SHB20 fuel, the second-generation biofuel containing 20% FAME/hydrotreated vegetable oil (HVO), after a whole-body exposure with and without diesel particle filter (DPF). The experiment was performed on 95 male Fischer 344 rats, divided into 10 groups (8 experimental, 2 control). Animals were exposed to DEE (diluted with charcoal-filtered room air to 2.1-2.2% (v/v)) for 7 or 28 days (6 h/day, 5 days/week) in an inhalation chamber. DEE originated from Euro 5 engine with or without DPF treatment, run on B7 or SHB20 fuel. Animals in the control groups were exposed to clean air. Our results showed that the majority of haematological and biochemical parameters examined in blood were at a similar level in the exposed and control animals. However, exposure to DEE from the SHB20 fuel caused an increase in the number of red blood cells (RBC) and haemoglobin concentration. Moreover, 7 days exposure to DEE from SHB20 fuel induced genotoxic effects manifested by increased levels of DNA single-strand breaks in peripheral blood lymphocytes. Furthermore, inhalation of both types of DEE induced oxidative stress and caused imbalance of anti-oxidant defence enzymes. In conclusion, exposure to DEE from B7, which was associated with higher exposure to polycyclic aromatic hydrocarbons, resulted in decreased number of T and NK lymphocytes, while DEE from SHB20 induced a higher level of DNA single-strand breaks, oxidative stress and increased red blood cells parameters. Additionally, DPF technology generated increased number of smaller PM and made the DEE more reactive and more harmful, manifested as deregulation of redox balance.


Assuntos
Poluentes Atmosféricos/toxicidade , Quebras de DNA de Cadeia Simples , Eritrócitos/efeitos dos fármacos , Estresse Oxidativo , Emissões de Veículos/toxicidade , Animais , Contagem de Eritrócitos , Ácidos Graxos/química , Ácidos Graxos/toxicidade , Hidrogenação , Masculino , Óleos de Plantas/química , Óleos de Plantas/toxicidade , Ratos , Ratos Endogâmicos F344 , Testes de Toxicidade
2.
Toxicol Appl Pharmacol ; 313: 35-46, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27746313

RESUMO

The growing use of silver nanoparticles (AgNPs) in various applications, including consumer, agriculture and medicine products, has raised many concerns about the potential risks of nanoparticles (NPs) to human health and the environment. An increasing body of evidence suggests that AgNPs may have adverse effects of humans, thus the aim of this study was to investigate the effects of AgNPs on the male reproductive system. Silver particles (20nm AgNPs (groups Ag I and Ag II) and 200nm Ag sub-micron particles (SPs) (group Ag III)) were administered intravenously to male Wistar rats at a dose of 5 (groups Ag I and Ag III) or 10 (group Ag II) mg/kg of body weight. The biological material was sampled 24h, 7days and 28days after injection. The obtained results revealed that the AgNPs had altered the luteinising hormone concentration in the plasma and the sex hormone concentration in the plasma and testes. Plasma and intratesticular levels of testosterone and dihydrotestosterone were significantly decreased both 7 and 28days after treatment. No change in the prolactin and sex hormone-binding globulin concentration was observed. Exposure of the animals to AgNPs resulted in a considerable decrease in 5α-reductase type 1 and the aromatase protein level in the testis. Additionally, expression analysis of genes involved in steroidogenesis and the steroids metabolism revealed significant down-regulation of Star, Cyp11a1, Hsd3b1, Hsd17b3 and Srd5a1 mRNAs in AgNPs/AgSPs-exposed animals. The present study demonstrates the potential adverse effect on the hormonal regulation of the male reproductive function following AgNP/AgSP administration, in particular alterations of the sex steroid balance and expression of genes involved in steroidogenesis and the steroids metabolism.


Assuntos
Hormônios Esteroides Gonadais/fisiologia , Nanopartículas/toxicidade , Reprodução/efeitos dos fármacos , Prata/química , Animais , Masculino , Nanopartículas/química , Ratos , Ratos Wistar
3.
J Appl Toxicol ; 32(11): 920-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22696427

RESUMO

Silver nanoparticles (AgNPs) are the most commonly used nanoparticles owing to their antimicrobial properties. The motivation of the present study was (1) to analyze the effect of silver particle size on rat tissue distribution at different time points, (2) to determine the accumulation of AgNPs in potential rat target organs, (3) to analyze the intracellular distribution of AgNPs and (4) to examine the excretion of AgNPs by urine and feces. AgNPs were characterized by dynamic light scattering (DLS), zeta potential measurements, BET surface area measurements, transmission and scanning electron microscopy. AgNPs (20 and 200 nm) were administered intravenously (i.v.) to male Wistar rats at a dose of 5 mg kg(-1) of body weight. Biological material was sampled 24 h, 7 and 28 days after injection. Using inductively coupled plasma-mass spectrometry (ICP-MS) and transmission electron microscopy (TEM) it was observed that AgNPs translocated from the blood to the main organs and the concentration of silver in tissues was significantly higher in rats treated with 20 nm AgNPs as compared with 200 nm AgNPs. The highest concentration of silver was found in the liver after 24 h. After 7 days, a high level of silver was observed in the lungs and spleen. The silver concentration in the kidneys and brain increased during the experiment and reached the highest concentration after 28 days. Moreover, the highest concentration of AgNPs was observed in the urine 1 day after the injection, maintained high for 14 days and then decreased. The fecal level of silver in rats was the highest within 2 days after AgNPs administration and then decreased.


Assuntos
Nanopartículas Metálicas/química , Prata/metabolismo , Animais , Relação Dose-Resposta a Droga , Fezes/química , Fígado/metabolismo , Masculino , Espectrometria de Massas , Nanopartículas Metálicas/administração & dosagem , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Ratos , Ratos Wistar , Prata/administração & dosagem , Distribuição Tecidual
4.
Acta Biochim Pol ; 45(3): 695-9, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9918496

RESUMO

A high level of the nucleotide sequence conservation of mitochondrial nad3 and rps12 genes was found in four lupin species. The only differences concern three nucleotides in the Lupinus albus rps12 gene and three nucleotides insertion in the L. mutabilis spacer. Northern blot analysis as well as RT-PCR confirmed cotranscription of the L. luteus genes because the transcripts detected were long enough.


Assuntos
DNA Mitocondrial/genética , Proteínas Mitocondriais , Proteínas de Plantas/genética , Plantas/genética , Sequência de Bases , Northern Blotting , Primers do DNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...