Avaliação do potencial imunotóxico do herbicida diuron: estudo de toxicidades de 28 e 90 dias(doses repetidas)
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Data
2007-02-26
Autores
Domingues, Alexandre [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Escassas informações são encontradas na literatura a respeito do potencial imunotóxico do Diuron, um herbicida derivado da uréia, utilizado no Brasil e no mundo nas lavouras de café, cana-de-açúcar, algodão, abacaxi, citros, alfafa e trigo. Desta forma, o presente estudo teve por objetivo investigar a toxicidade do Diuron sobre o sistema imunológico. Para isso, foram avaliados parâmetros gerais de toxicidade, bioquímicos, hematológicos, histopatologia de órgãos linfohematopoiéticos e fenotipagem de linfócitos T CD4, T CD8 e B de ratos Wistar machos. Foram utilizados dois protocolos experimentais: I - toxicidade aguda (28 dias) e II - toxicidade subcrônica (90 dias) sendo os animais expostos ao Diuron por via oral (adicionado à ração), nas concentrações de 125, 1250 e 2500 ppm. A exposição ao Diuron resultou em diminuição do ganho de peso corpóreo médio nos grupos 1250 e 2500 ppm aos 28 e 90 dias acompanhada pela redução do consumo de ração. O peso relativo do baço e dos rins foi maior nas três concentrações de Diuron aos 28 dias, e apenas em 2500 ppm, aos 90 dias. O peso relativo do fígado foi maior em 1250 e 2500 ppm aos 28 dias e apenas em 2500 ppm aos 90 dias. Aos 28 dias, os níveis de albumina e proteína total foram maiores nos três grupos expostos e os níveis de creatinina e uréia aumentaram apenas no grupo 2500 ppm. A análise histológica revelou que o Diuron, especialmente na maior concentração levou à depleção de polpa branca no baço, associada a redução do número de linfócitos T CD4+ e aumento de hematopoiese extramedular, deposição de hemosiderina e hiperplasia eritróide na polpa vermelha. Não foram observadas alterações hematológicas importantes. Com relação à análise fenotípica das subpopulações de linfócitos, observamos uma redução de células CD4+...
Few information is available regarding immunotoxic potential of Diuron, a phenylurea herbicide widely used in Brazil and around the world on sugar cane, cotton, coffee, pineapple, citros, alfafa and wheat crops.The objective of the present study was to evaluate the toxicity of Diuron in the immune system. General parameters of toxicity were evaluated and biochemistry, hematology, histologic aspects of lymphohematopoietic organs and CD4+, CD8+ and CD45RA+ splenic lymphocytes subpopulations of male Wistar rats. Two experimental protocols were used: I Acute toxicity (28 days) and II Sub-Chronic toxicity (90 days) and the animals were treated with 125 ppm, 1250 ppm and 2500 ppm of Diuron by feeding. The experimental groups treated with Diuron at 1250 ppm and 250o ppm, showed decreased body weight gain after 28 and 90 days of treatment, corresponding with the reduced food intake. The relative weight of the spleen and kidneys were higher at the three concentrations in the end of 28 days, and only at 2500 ppm after 90 days. The relative weight of the liver was higher at 1250 ppm and 2500 ppm to the 28 days, and only at 2500 ppm to the 90 days of treatment. After 28 days, the albumin and total protein serum levels were higher at the three treated groups and the creatine and urea higher only at 2500 ppm of Diuron. The treatment with Diuron at higher doses causes the depletion of the lymphoid white pulp and increases the hemosiderin deposition in the red pulp. We didn't observed significant hematological alterations between the treated and control groups. Regarding fenotipic analysis of splenic lymphocytes, it was observed a decrease in CD4+ subpopulations at 1250 ppm and 2500 ppm in the end of 28 days, and only at 2500 ppm after 90 days of treatment compared with the control groups values. Concluding, Diuron had a systemic toxic effect and also on lymphohematopoietic organs.
Few information is available regarding immunotoxic potential of Diuron, a phenylurea herbicide widely used in Brazil and around the world on sugar cane, cotton, coffee, pineapple, citros, alfafa and wheat crops.The objective of the present study was to evaluate the toxicity of Diuron in the immune system. General parameters of toxicity were evaluated and biochemistry, hematology, histologic aspects of lymphohematopoietic organs and CD4+, CD8+ and CD45RA+ splenic lymphocytes subpopulations of male Wistar rats. Two experimental protocols were used: I Acute toxicity (28 days) and II Sub-Chronic toxicity (90 days) and the animals were treated with 125 ppm, 1250 ppm and 2500 ppm of Diuron by feeding. The experimental groups treated with Diuron at 1250 ppm and 250o ppm, showed decreased body weight gain after 28 and 90 days of treatment, corresponding with the reduced food intake. The relative weight of the spleen and kidneys were higher at the three concentrations in the end of 28 days, and only at 2500 ppm after 90 days. The relative weight of the liver was higher at 1250 ppm and 2500 ppm to the 28 days, and only at 2500 ppm to the 90 days of treatment. After 28 days, the albumin and total protein serum levels were higher at the three treated groups and the creatine and urea higher only at 2500 ppm of Diuron. The treatment with Diuron at higher doses causes the depletion of the lymphoid white pulp and increases the hemosiderin deposition in the red pulp. We didn't observed significant hematological alterations between the treated and control groups. Regarding fenotipic analysis of splenic lymphocytes, it was observed a decrease in CD4+ subpopulations at 1250 ppm and 2500 ppm in the end of 28 days, and only at 2500 ppm after 90 days of treatment compared with the control groups values. Concluding, Diuron had a systemic toxic effect and also on lymphohematopoietic organs.
Descrição
Palavras-chave
Intoxicação, Herbicidas - Toxicologia - Estudos experimentais, Toxicidade, Diuron - Potencial imunotóxico, Immunotoxicity
Como citar
DOMINGUES, Alexandre. Avaliação do potencial imunotóxico do herbicida diuron: estudo de toxicidades de 28 e 90 dias(doses repetidas). 2007. 72 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, 2007.