Influência da mistura de cinco praguicidas em baixas doses sobre o sistema reprodutor de ratas Aprague-Dawley, Wistar e Lewis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mistura de praguicidas em baixas doses: verificação de desregulação endócrina em ratos Lewis machos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Exposição à mistura de pesticidas em baixas doses: validação de método e aplicação a tecido adiposo de animais de experimentação (ratos Lewis)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Resíduos de pesticidas em tecido adiposo associado a órgãos reprodutivos: validação de método analítico e aplicação a animais de experimentação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Ação de mistura de praguicidas no sistema reprodutor de ratos Lewis machos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Proliferação e Morte Celular (Apoptose) avaliadas em ratos Lewis após tratamento com mistura de praguicidas em baixas doses

The use of pesticides in Brazil has intensified over the years. And since 2009 it was ranked as the largest market for pesticides worldwide. The consequential diffuse contamination of the environment is therefore due to the increasing number of chemicals of different classes, origins and modes of action. Little is known about the action of pesticides on human health in situations of co-exposure. Possible toxic effects are not restricted to agricultural and industrial workers, but also the general population that may be exposed continuously to its residues in food and water. Although these pesticides are mostly present in the environment at low doses, it must be considered that possible cumulative or synergistic effects may occur when there are concurrent or sustained exposure for two or more of these agents, which can lead to late manifestation of subclinical damages, sometimes irreversible. Thus, the specific objective of this study was to assess the effect of carcinogenesis promotion of a mixture of pesticides at low doses and analyze the phenomena of cell proliferation and apoptosis in rat liver. A total of 50 male Lewis rats was separated into 5 groups for 8 weeks in a medium term hepatocarcinogenesis model. The three different classes of pesticides (dieldrin, dicofol, endosulfan, dichlorvos and permethrin), whose residues were detected by ANVISA during the period from 2001 to 2005 in tomatoes cultures, were added to the feed of rats initiated to hepatocarcinogenesis with diethylnitrosamine (DEN- 200mg/kg ip). We used two different mixtures, one with no toxic effects at doses (MEX1) referring to the NOEL (no-observed-effect level) and another at doses LOEL / LEL / LOAEL (Lowest-observed-effect level / Lowest-effect level / Lowest -observed-adverse-effect level), to the installation of adverse effects (MEX2), derived from chronic studies. All animals ...(Complete abstract click electronic access below)

Effects of a Mixture of Pesticides on the Adult Female Reproductive System of Sprague-Dawley, Wistar, and Lewis Rats

The Brazilian federal government Agency for Health Surveillance detected pesticide residues in fresh food available for consumers all over the country. The current study investigated the effects of a mixture of some of those pesticides (dichlorvos, dicofol, dieldrin, endosulfan, and permethrin) on the reproductive system of Sprague-Dawley (SD), Wistar (WT), and Lewis (LEW) rats. Female rats from each strain were randomized into three experimental groups and were fed a control diet or diets added with pesticides mixture at their respective no-observed-effect level (NOEL)/no-observed-adverse-effect level (NOAEL) (low dose) (mg/kg/d): dichlorvos (0.23), dicofol (0.5), dieldrin (0.025), endosulfan (0.7), permethrin (5), or lowest-observed-effect level (LOEL)/lowest-effect level (LEL)/ lowest-observed-adverse-effect level (LOAEL) (toxically effective dose) (mg/kg/d): dichlorvos (2.3), dicofol (2.1), dieldrin (0.05), endosulfan (3.8), and permethrin (25) as reported in the literature. Euthanasia was performed between wk 10 and 12, during the estrous stage. Decreased body weights gain (SD and WT) and increased liver weights (SD, WT, and LEW) were observed in each strain fed the pesticides mixture at the higher levels. At that dose level, rat strains also varied in their responses regarding the estrous cycle, hormonal levels, and number of developing ovarian follicles. The studied mixture of pesticides was found to interfere with the female reproductive system when individual pesticides were mixed above a certain level, indicating a threshold exists for each of the strains studied.