Soil from local beech-forest, spruce-forest and an industrial area was taken. Control- and test-microcosms containing 150 ml soil were spiked with cypermethrin 0,4 mg/ml soil. Cypermethrin residues were extracted on day seven and 14. Cyclohexane and deionized water was utilized in multiple step extraction processes. Samples were analyzed in a Gas Chromatograph (GC) with electron capture detector (ECD). Concentration values for the samples were highest for beech-forest soil and lower for the other two soil-types. Statistical differences in concentrations between control- and test-microcosms for each soil-type on day seven and day 14 were evaluated with Mann Whitney U tests. Significant result was only found in the industrial 14-day group. The small amounts of cypermethrin in the extracts could not only be ascribed to a bacterial degradation process. Used insecticide has a high bonding affinity for particles and is sequestered in soil.

The peripheral-type benzodiazepine receptor (PTBR) of trout brain was pharmacologically characterized and pyrethroid interaction with this site investigated. High-affinity binding sites for [³H]PK 11195 were detected in brain membranes of rainbow trout; these shared some of the characteristics of the PTBR of rodent brain (i.e., high affinity for PK 11195 and an endogenous ligand protoporphyrin IX) but were unique in the low affinity for Ro5-4864. Permethrin displaced [³H]PK 11195 binding with micromolar affinity while deltamethrin had less than 50% efficacy at displacement. Thus the PTBR appeared not to be relevant to pyrethroid toxicity in rainbow trout. Pyrethroid interaction with the GABA, receptor was investigated using [³⁵S]TBPS as a radioligand probe and by measurement of GABA-stimulated ³⁶c1- influx in vesicle preparations. At micromolar concentrations, deltamethrin, cypermethrin isomers and other pyrethroids inhibited [³⁵S]TBPS binding by 55- 95% with limited stereoselectivity. Pyrethroids were found to effect a GABAdependent inhibition of [³⁵S]TBPS binding. Ro5-4864, which showed micromolar affinity for the trout PTBR, produced a GABA-modulated interaction with [³⁵S]TBPS binding. These results delineate the reciprocal allosteric interactions between a pyrethroid binding site, a Ro5-4864 binding site, the GABA recognition moiety and the TBPS binding site in trout brain. However, pyrethroids exhibited a modest affinity for this binding site on the GABAA receptor. Pyrethroids indirectly inhibited the GABA-dependent influx of ³⁶Cl⁻into trout brain synaptoneurosomes by increasing the basal uptake of chloride, thereby compromising the ability of the vesicles to respond to applications of GABA. This pyrethroid effect was of nanomolar potency, stereospecific, tetrodotoxinsensitive and mimicked by veratridine. These results suggest that the primary effect of pyrethroids in trout brain, as measured by this assay, was due to an interaction with voltage-dependent sodium channels, increasing sodium conductance and thereby increasing the basal uptake of ³⁶Cl⁻ through a voltagesensitive channel. The convulsant activity of deltamethrin was tested in rainbow trout. The EC₅₀ for convulsant severity was 32 μg /kg body weight. By comparison, pyrethroids at these concentrations in rodents produce no overt toxicity but act as potent proconvulsants. / Graduation date: 1990

Research aim and objectives. To investigate species diversity of pollen beetles (Meligethes s.l.) in WOSR and SOSR crops during flowering stage and to evaluate the resistance of pollen beetle (M. aeneus) to pyrethroid class insecticides. Research objectives: ● To estimate species diversity of pollen beetles (Meligethes s.l.) in WOSR and SOSR agrocenoses during flowering stage in the regions of intensive oilseed rape growing by morphologic and molecular (DNA sequencing) methods and to evaluate the species diversity (Simpson’s) index; • To evaluate the genetic diversity of the most common species of pollen beetles (Meligethes s.l.) in oilseed rape agrocenoses and to compare them with the deponated data in the GenBank; • To evaluate the resistance of populations of pollen beetle (M. aeneus), collected from different regions, to active substances of pyrethroid class insecticides: λ- cyhalothrin, α- cypermethrin, deltamethrin and tau – fluvalinate by IRAC (Insecticide Resistance Action Committee) method and to determine the variation in the resistance of pollen beetle during the research period; • To determine the resistance of pollen beetle (M. aeneus) to pyrethroid class insecticides in the field conditions; • To determine the effectiveness of insecticides with different modes of action (pyrethroid, neonicotinoid, phosphorus-organic) against pollen beetle (M. aeneus) in the field conditions and to evaluate their effect on the productivity of WOSR and SOSR. Scientific novelty of... [to full text] / Tyrimų tikslas ir uždaviniai. Ištirti žiedinukų (Meligethes s.l.) rūšinę sudėtį žieminių ir vasarinių rapsų pasėliuose žydėjimo tarpsniu, atskirų rūšių išplitimą bei įvertinti rapsinio žiedinuko (M. aeneus) atsparumą piretroidų klasės insekticidams. Tyrimų uždaviniai: • Nustatyti žiedinukų (Meligethes s.l.) rūšinę sudėtį žieminių ir vasarinių rapsų agrocenozėse žydėjimo tarpsniu intensyvaus rapsų auginimo regionuose morfologiniu ir molekuliniu (DNR sekoskaitos) metodais bei įvertinti žiedinukų (Meligethes s.l.) rūšių išplitimo indeksą; • Įvertinti dažniausiai aptinkamų rapsų agrocenozėse žiedinukų (Meligethes s.l.) rūšių genetinį polimorfizmą bei palyginti su Genų banke deponuotais duomenimis; • Įvertinti rapsinio žiedinuko (M. aeneus) populiacijų iš skirtingų regionų atsparumą piretroidų klasės insekticidų veikliosioms medžiagoms: lambda-cihalotrinui, alfa-cipermetrinui, deltametrinui ir tau-fluvalinatui IRAC metodu bei nustatyti rapsinio žiedinuko atsparumo pokyčius per tyrimų laikotarpį; • Nustatyti rapsinio žiedinuko (M. aeneus) atsparumą piretroidų klasės insekticidams lauko sąlygomis; • Nustatyti skirtingų klasių insekticidų (piretroidų, neonikotinoidų, fosforoorganinių junginių) veiksmingumą nuo rapsinio žiedinuko (M. aeneus) lauko sąlygomis bei įvertinti jų poveikį žieminių ir vasarinių rapsų derlingumo rodikliams. Mokslinis darbo naujumas. Morfologiniu bei DNR sekvenavimo metodais nustatyta Meligethes s.l. populiacijų rūšinė sudėtis bei įvertintas rūšių išplitimas... [toliau žr. visą tekstą]

Helicoverpa armigera is a polyphagous pest. Due to excessive use of insecticides, the field populations of H. armigera have become resistant to synthetic pyrethroids by one or combination of three mechanisms / reduced penetration through the cuticle, decreased nerve sensitivity and enhanced metabolism by the detoxification enzymes especially glutathione S-transferases. In this study, gut sections of H. armigera were obtained from Adana and Antalya field populations and susceptible populations from Israel. Each gut section was homogenized separately in 1.0 ml, 40 mM and pH 7.5 phosphate buffers. GST activity was determined using CDNB as substrate. Product formation linearly increased up to 29.5&micro / g proteins in 20mM, pH 7.5 phosphate buffers. Maximum reaction rate was reached at 30&amp / #9702 / C. The Vmax and Km values for GST towards CDNB and GSH were calculated with Lineweaver-Burk and Eadie-Scatchard plots as CDNB Vmax / 6.54&micro / mol/min/mg, 6.35&micro / mol/min/mg , Km / 0.29mM, 0.28mM ,respectively and as GSH Vmax / 6.42&micro / mol/min/mg, 6.65&micro / mol/min/mg, Km / 0.22mM, 0.23mM, respectively. Cytosolic GST activity of each individual from Adana, Antalya and susceptible populations were determined under optimized conditions. The mean of GST activity in Adana population (n=50) and Antalya population (n=50) were found 7.824&micro / mol/min/mg and 9.518&micro / mol/min/mg, respectively. The mean of GST activity in susceptible population (n=50) was determined as 3.272&micro / mol/min/mg. According to these results, GST activities of Adana and Antalya field populations&rsquo / showed statistically significant increase (p&lt / 0.05) than susceptible H. armigera populations with ANOVA method. In addition, Antalya population showed statistically increase (p&lt / 0.05) GST activity than Adana.

Male fertility is largely controlled by the hypothalamic-pituitary axis, a careful balance between stimulating and suppressing gene expression and the secretion of hormones. The critical factors for male fertility have in the past been thought to be limited to testosterone and the gonadotropins. Estrogen has only recently been demonstrated to be both a crucial requirement for fertility and a cause of infertility. Reports in the early 1990s demonstrated a decrease in mean sperm counts over the last 50 years. A hypothesis for this observation is the increase of xenoestrogens in the environment that are able to mimic and potential disrupt the natural estrogens involvement in fertility. Although the mechanisms of estrogens involvement are not yet defined, the Sertoli cells are a potential sites of action as they possess receptors for the hormone and are able to locally produce it. Sertoli cells both act to protect and provide for the male germ cells and the developing spermatozoa. Pyrethroids are common synthetic insecticides of which some have previously shown estrogenic activity. Therefore this investigation examined the effects of pyrethoids, whose estrogenicity was confirmed via the yeast assay, on the estrogen receptor expression in mouse Sertoli cells as a model for general effects of estrogenic chemicals on male fertility. The results first confirmed the estrogenicity of some pyrethroids and these pyrethroids when exposed to mouse Sertoli cells effected estrogen receptor mRNA expression however in a different way to the natural ligand 17β-estradiol.

Thesis (Ph.D. (Physiology))--Mahidol University, 1984.

Made available in DSpace on 2014-06-11T19:27:58Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-06-28Bitstream added on 2014-06-13T20:57:23Z : No. of bitstreams: 1 bariani_mh_me_botfmvz.pdf: 2706656 bytes, checksum: ad8c8dec4b880f364d61ead29ac9bf62 (MD5) / Universidade Estadual Paulista (UNESP) / o carcinoma espontâneo de mama representa cerca de 50% de todas as neoplasias malignas que acometem a cadelas adultas e demonstram semelhanças ao câncer de mama em mulheres. A exposição humana e de outros animais a contaminantes ambientais podem estar associados ao desenvolvimento do câncer de mama. O objetivo foi identificar resíduos dos piretróides aletrina, lambda- cialotrina, cipermetrina, deltametrina e tetrametrina no tecido adiposo adjacente de tumores malignos em mama de cadelas com e sem tumor espontâneo, por Cromatografia Liquida de Alta Eficiência (HPLC) e correlacionar com a expressão morfológica e o grau de agressividade dos tumores por meio do exame histopatológico. Foram utilizadas 60 cadelas sem predileção por raça, de idade superior a cinco anos. Esses animais foram distribuídos em dois grupos de 30 animais. Grupo 1: cadelas com diagnóstico citopatológico e histopatológico de carcinoma espontâneo de mama; G2: cadelas sem diagnóstico de tumor de mama. Em ambos, foram colhidos 5 gramas de tecido adiposo adjacente ao tecido mamário, que permaneceu em refrigeração (-4°C) até o momento da análise pela técnica de HPLC. Para o diagnóstico e classificação das neoplasias utilizaram-se os critérios da Organização Mundial da Saúde. Não houve diferença significativa entre os grupos (P>O,05); entretanto quando comparado o nível de piretróides entre os carcinomas do Grupo 1, verificou-se a prevalência significativa (P<O,05) nos carcinomas complexo em relação aos simples. O presente resultado sugere a probabilidade dos resíduos de piretróides como contaminantes ambientais possam estar envolvidos no processo de desenvolvimento do carcinoma de mama em cadela / Spontaneous mammary carcinoma represents about 50% of ali the malignant neoplasias that assail adult female dogs and it demonstrates similarities to breast cancer in women. The exposure of humans and other animais to environmental pollutants can be associated to the development of breast cancer. The objective was to identify residues of the pyrethroids alethrin, lambda-cialothrin, cypermethrin, deltamethrin and tetramethrin in the adipose tissue adjacent to malignant tumors in the mammary gland of female dogs with and without spontaneous tumor by High Performance/Pressure Liquid Chromatography (HPLC) test; to correlate the results with the morphologic expression and the degree of aggressiveness of the tumors through the histopathology exam. Sixty female dogs were used without predilection of race, at or superior to five years of age. The animais were divided in two groups: G1- 30 female dogs with cytopathologic and histopathologic diagnosis of spontaneous mammary carcinoma and G2- 30 female dogs diagnosed without mammary tumors. In both, 5 grams of adipose tissue adjacent to the mammary gland was collected, and was refrigerated at (-4°C) until the moment it was analyzed by the HPLC technique. For the diagnosis and classification of the neoplasias the criteria from the World Organization of Health were used. There was no significant difference among the groups (P>0,05); however when compared the levei of pyrethroids among the carcinomas of Group 1, the significant prevalence was verified (P <0,05) in the compound carcinomas in relation to the simple. The present results suggest the probability that residues of the pyrethroids as environmental pollutants can be involved in the process of mammary development carcinoma in female dog's mammary gland

Orientador: Noeme Sousa Rocha / Banca: Domingos José Sturion / Banca: Alaor Aparecido Almeida / Resumo: o carcinoma espontâneo de mama representa cerca de 50% de todas as neoplasias malignas que acometem a cadelas adultas e demonstram semelhanças ao câncer de mama em mulheres. A exposição humana e de outros animais a contaminantes ambientais podem estar associados ao desenvolvimento do câncer de mama. O objetivo foi identificar resíduos dos piretróides aletrina, lambda- cialotrina, cipermetrina, deltametrina e tetrametrina no tecido adiposo adjacente de tumores malignos em mama de cadelas com e sem tumor espontâneo, por Cromatografia Liquida de Alta Eficiência (HPLC) e correlacionar com a expressão morfológica e o grau de agressividade dos tumores por meio do exame histopatológico. Foram utilizadas 60 cadelas sem predileção por raça, de idade superior a cinco anos. Esses animais foram distribuídos em dois grupos de 30 animais. Grupo 1: cadelas com diagnóstico citopatológico e histopatológico de carcinoma espontâneo de mama; G2: cadelas sem diagnóstico de tumor de mama. Em ambos, foram colhidos 5 gramas de tecido adiposo adjacente ao tecido mamário, que permaneceu em refrigeração (-4°C) até o momento da análise pela técnica de HPLC. Para o diagnóstico e classificação das neoplasias utilizaram-se os critérios da Organização Mundial da Saúde. Não houve diferença significativa entre os grupos (P>O,05); entretanto quando comparado o nível de piretróides entre os carcinomas do Grupo 1, verificou-se a prevalência significativa (P<O,05) nos carcinomas complexo em relação aos simples. O presente resultado sugere a probabilidade dos resíduos de piretróides como contaminantes ambientais possam estar envolvidos no processo de desenvolvimento do carcinoma de mama em cadela / Abstract: Spontaneous mammary carcinoma represents about 50% of ali the malignant neoplasias that assail adult female dogs and it demonstrates similarities to breast cancer in women. The exposure of humans and other animais to environmental pollutants can be associated to the development of breast cancer. The objective was to identify residues of the pyrethroids alethrin, lambda-cialothrin, cypermethrin, deltamethrin and tetramethrin in the adipose tissue adjacent to malignant tumors in the mammary gland of female dogs with and without spontaneous tumor by High Performance/Pressure Liquid Chromatography (HPLC) test; to correlate the results with the morphologic expression and the degree of aggressiveness of the tumors through the histopathology exam. Sixty female dogs were used without predilection of race, at or superior to five years of age. The animais were divided in two groups: G1- 30 female dogs with cytopathologic and histopathologic diagnosis of spontaneous mammary carcinoma and G2- 30 female dogs diagnosed without mammary tumors. In both, 5 grams of adipose tissue adjacent to the mammary gland was collected, and was refrigerated at (-4°C) until the moment it was analyzed by the HPLC technique. For the diagnosis and classification of the neoplasias the criteria from the World Organization of Health were used. There was no significant difference among the groups (P>0,05); however when compared the levei of pyrethroids among the carcinomas of Group 1, the significant prevalence was verified (P <0,05) in the compound carcinomas in relation to the simple. The present results suggest the probability that residues of the pyrethroids as environmental pollutants can be involved in the process of mammary development carcinoma in female dog's mammary gland / Mestre

Submitted by (edna.saturno@ufrpe.br) on 2016-11-21T15:38:16Z No. of bitstreams: 1 Agna Rita dos Santos Rodrigues.pdf: 1761082 bytes, checksum: 33ad0d0702f86a28c68a0fe70066f3f7 (MD5) / Made available in DSpace on 2016-11-21T15:38:16Z (GMT). No. of bitstreams: 1 Agna Rita dos Santos Rodrigues.pdf: 1761082 bytes, checksum: 33ad0d0702f86a28c68a0fe70066f3f7 (MD5) Previous issue date: 2012-02-21 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Insecticides and natural enemies are used or preserved sharing the same objective of reducing pest populations in the crop ecosystems. However, the examples of simultaneous action with additive or synergistic outcomes are rare. The resistance in lady beetles to the insecticide lambda-cyhalothrin, which is widely used against pests nontarget of the lady beetles, can result in simultaneous use of chemical and at least partial biological control. In this study was investigated the susceptibility of 28 Brazilian and 2 North American lady beetle populations to the lambda-cyhalothrin. Furthermore, studies were conducted to characterize the mechanisms and the inheritance of resistance for those species exhibiting high levels of tolerance to lambda-cyhalothrin. Among the studied populations resistance ratios were determined varying from 115- to 38-fold in four populations of Eriopis connexa Germar and 220-fold in one North American population of Hippodamia convergens Guérin-Méneville; therefore, there is strong evidence for selection of resistance to lambda-cyhalothrin in the field. Further, 22 and 96% of the Brazilian populations exhibited LD50 value that exceed the recommended lambda-cyhalothrin dose to spray cotton fields and the LD50 calculated for boll weevil (Anthonomus grandis Boh.). The lady beetle E. connexa exhibited autosomal and incompletely dominant inheritance of resistance to lambda- cyhalothrin; while the knockdown effect for H. convergens was sex linked and incompletely recessive. The tests indicated polygenically inherited resistance for both species with effective dominance varying as function of the dose applied. Resistance in E. connexa was completely inhibited with piperonyl butoxide (PBO), while the resistance in H. convergens was only partially inhibited with this synergist. High level of esterase activity was found in the resistant population of E. connexa. These results show the first record of resistance for lady beetles in Brazil and the first characterization of inheritance of resistance and metabolism related to insecticide resistance in lady beetles in the world. / Inseticidas e inimigos naturais são empregados nos agroecossistemas dividindo o mesmo objetivo de reduzir populações de pragas. No entanto, raros são os exemplos da ação simultânea com resultados aditivos ou sinergistas de controle. A resistência em joaninhas ao lambda-cialotrina, produto utilizado para o controle de pragas não alvo das joaninhas, pode resultar em uso simultâneo do controle biológico e químico. Assim, neste estudo foi investigada a suscetibilidade de 28 populações brasileiras de oito espécies de joaninhas e duas populações de joaninhas norte americanas ao inseticida lambda-cialotrina, bem como a caracterização dos mecanismos e herança da resistência em espécies com alto grau de tolerância. Entre as populações e espécies estudadas foram determinadas razões de resistência variando de 11- a 38-vezes em quatro populações de Eriopis connexa Germar e de 220-vezes para a população americana de Hippodamia convergens Guérin-Méneville, sendo assim consideradas como selecionadas em campo para resistência ao lambda-cialotrina. Além disso, baseado na DL50 de sete espécies estudadas com ocorrência natural em algodoeiro, 22 e 96% das populações foram mais tolerantes à maior dose recomendada do lambda-cialotrina para uso na cultura do algodão e a DL50 estimada para Anthonomus grandis Boh., respectivamente. A população estudada de E. connexa possui herança da resistência autossomal e incompletamente dominante, enquanto que a resistência knockdown em H. convergens é ligado ao sexo e incompletamente recessiva. Os testes indicaram herança poligênica para E. connexa. Para E. connexa e H. convergens, a dominância efetiva variou em função da dose utilizada. O butóxido de piperonila (PBO) inibiu completamente o metabolismo do lambda-cialotrina em E. connexa, tornando a população resistente similar a população suscetível, enquanto que em H. convergens, o metabolismo foi apenas parcialmente inibido por este sinergista.Vale ressaltar que foi observada alta atividade de esterases na população resistente de E. connexa. Estes resultados compõem o primeiro relato de resistência de joaninhas à inseticida no Brasil e a primeira caracterização da herança e metabolismo quanto à resistência de joaninhas no mundo.

Orientador: Miguel Arcanjo Areas / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-09T20:50:29Z (GMT). No. of bitstreams: 1 Santos_MonicaAlessandraTeixeirados_D.pdf: 1218402 bytes, checksum: c91dd447b33272e2f271723339af18ec (MD5) Previous issue date: 2008 / Resumo: Ratos Wistar recém desmamados foram expostos, por via oral, a deltametrina e permetrina para avaliação dos efeitos cardiotóxicos assim como o provável efeito protetor de fibras alimentares sobre a ação desses piretróides. O trabalho teve como objetivos específicos à avaliação eletrocardiográfica, o estudo histológico do fígado e coração e a determinação de resíduos no coração e fígado dos animais experimentais. Para tanto, o trabalho foi dividido em três partes: 1) Ensaio agudo, 2) Ensaio subcrônico, 3) Ensaio subcrônico + administração de fibras. Na primeira fase do experimento, os animais receberam doses equivalentes à 1/2 DL50, 1/5 DL50 e 1/10 DL50 de permetrina e deltametrina em dose única, com o objetivo de se determinar a menor dose onde se observa efeito agudo (LOAEL). Durante o ensaio biológico, os inseticidas foram administrados por gavagem com a utilização de óleo de milho (5 mL/kg) como veículo. Os animais do grupo controle receberam apenas óleo de milho, nas mesmas condições. Após a realização dos eletrocardiogramas (ECG) constatou-se que administração de 1/10 DL50 de permetrina e deltametrina foi a melhor dose para a realização do ensaio subcrônico de 28 dias. Durante o ensaio subcrônico, os piretróides foram administrados, diariamente, nas mesmas condições do ensaio agudo tendo sido verificado no ECG dos animais experimentais efeito cronotrópico negativo, prolongamento do intervalo PR e do complexo QRS, sugerindo retardo na condução dos estímulos dos átrios para os ventrículos. Além disso, o prolongamento dos intervalos QT e QTc indicaram retardo no processo de despolarização e repolarização ventricular, sugerindo risco de morte súbita. O complexo QRS apresentou maior prolongamento somente nos animais que receberam a deltametrina. Na terceira fase do experimento, foi avaliado o possível efeito protetor da pectina (fibra solúvel) e da celulose (fibra insolúvel), sobre a ação cardiotóxica dos piretróides, com a utilização da dose testada no ensaio subcrônico. A pectina se mostrou eficiente na redução dos efeitos tóxicos observados, já que sua presença aumentou a freqüência cardíaca e reduziu o intervalo PR, QT e QTc além do complexo QRS. A ingestão de celulose não alterou o quadro de toxicidade observado nos animais submetidos às substâncias testadas. Após o término dos ensaios subcrônicos, o coração e o fígado foram retirados dos animais experimentais para a avaliação histológica. O coração dos animais não apresentou alterações histológicas após a exposição a ambos os piretróides, no entanto, os fígados dos ratos que ingeriram deltametrina apresentaram células inflamatórias, hapatócitos irregulares, alterações citoplasmáticas, núcleo condensado e nucléolo indefinido. A exposição oral a permetrina induziu as mesmas alterações histológicas observadas nos fígados expostos a deltametrina, com exceção de infiltrações inflamatórias. A administração de pectina na dieta reduziu todas as alterações histológicas observadas anteriormente. No entanto, a celulose não se mostrou eficaz na proteção dos tecidos contra os efeitos histológicos dos piretróides estudados. Ao final do ensaio de toxicidade subcrônica, os resíduos de deltametrina e permetrina foram determinados no fígado e coração através do desenvolvimento/validação de método por cromatografia gasosa acoplada ao detector de captura de elétrons, não tendo sido detectada a presença destes resíduos nos tecidos estudados (LD < 0.9/0.2 para deltametrina e LD < 1/0.2 para permetrina em fígado e coração, respectivamente) / Abstract: The study was conducted on male wealing Wistar rats. They were exposed, by gavage, to deltamethrin and permethrin and the carditoxic effects of the pyrethroids and protective effects of dietary fibres were determinated. The purposes of this study were the eletrocardiographics evaluation, the histopathological study of the liver and heart and the residues determination in heart and liver of the rats. For that, this worky was divided in three parts: 1) Acute exposure, 2) Subchronic exposure, 3) Subchronic exposure + dietary fibres. In the first step, the animals were exposed to LD50, ½ LD50, 1/5 LD50 and 1/10 LD50 of permethrin and deltamethrin to determinate the lowest (LOAEL) dose which the acute effect could be observed. The insecticides were administrated in corn oil (5 ml/kg), intragastrically, in a single dose. Parallel studies were conduced in a control group that received only corn oil. The ECG records showed that 1/10 LD50 dose of permethrin and deltamethrin was the best dose for the conduction of subchronic assay. The experimental groups received the pyrethroids once a day for 28 days, in the same conditions of the first study. The subchronic poisoning resulted in negative chronotropism, prolongation of the PR interval and QRS complex, suggesting decrease of the stimulus from the atriums to ventricles. Besides, the prolongation of QT and QTc intervals indicated a decrease of the despolarization and repolarization processes suggesting sudden cardiac death. The QRS complex prolongation appeared only in the animals that received deltamethrin. In the third fase, the possible protective effects of pectin (soluble fiber) and cellulose (insoluble fiber) on pyrethroids cariotoxicity were evaluated. For this study, 1/10 LD50 dose was utilizated. Pectin increased the heart rate and decreased the PR, QT and QTc intervals and QRS complex, showing be efficient in reducing the cardiotoxicity. The ingestion of cellulose did not change the effects in heart observed in experimental animals. After the subchronic exposition, the heart and liver were taken in order to evaluate histologic changes. No changes were observed in the hearts of the rats exposed to both of pyrethroids. However, the liver of the animals exposed to deltamethrin showed inflamatory cells, irregular hepatocytes, cytoplasmatic changes, condensed nucleus and indefinite nucleolus. The permethrin induced the same histological changes observed in the livers exposed to the deltamethrin, exception of the inflamatory infiltrations. The pectin in the diet reduced all the histological changes previously observed and the cellulose did not efficient in the protection of the studied tissues. In the end of the subchronic essay, the tissue residues levels of permethrin and deltamethrin in heart and liver were estimated by gas chromatography with electron-capture detection. Residues of permethrin and deltamethrin were not observed in the studied tissues. (LOD < 0.9/0.2 for deltamethrin and LOD < 1.0/0.2 for permethrin in liver and heart, respectively) / Doutorado / Doutor em Ciência de Alimentos