title: Evaluation of toxic effects of a diet containing fish contaminated with methylmercury in rats mimicking the exposure in the Amazon riverside population.
abstract: This study was designed to evaluate the effects of a diet rich in fish contaminated with MeHg, mimicking the typical diet of the Amazon riverside population, in rats. Animals were randomly assigned to one of three groups with eight rats in each group: Group I-control, received commercial ration; Group II-received a diet rich in uncontaminated fish; Group III-received a diet rich in fish contaminated with MeHg. Treatment time was 12 weeks. Oxidative stress markers were evaluated, as well as the effects of this diet on DNA stability, systolic blood pressure (SBP), nitric oxide (NO) levels and histological damage in different tissues. There was a significant increase in SBP values in rats fed with MeHg-contaminated fish diet after the 10th week of the treatment. As far as oxidative stress biomarkers are concerned, no differences were observed in reduced glutathione and protein carbonyl levels, glutathione peroxidase, catalase, superoxide dismutase or δ-aminolevulinate dehydratase activities between the groups of animals receiving contaminated and uncontaminated fish diets. On the other hand, malondialdehyde levels increased significantly in rats fed with contaminated fish. NO levels were similar in all groups. DNA migration showed augmented in rats exposed to contaminated fish and histopathological analyses showed weak but significant leukocyte infiltration. Thus, we conclude that the MeHg-contaminated fish diet induced a slight lipid peroxidation and genotoxicity. However, these effects seem to be much less pronounced than when rats are exposed to aqueous solution containing CH3HgCl. Our findings support the contention that the chemical form of MeHg in fish or fish nutrients such as polyunsaturated fatty acids, Se or vitamin E could minimize the toxic effects of MeHg exposure in fish-eating communities.
authors: Departamento de Análises Clínicas, Toxicológicas e Bromatológicas, Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, 14040-903 Ribeirão Preto, São Paulo, Brazil.
authors: Denise
authors: D
authors: Grotto
authors: Juliana
authors: J
authors: Valentini
authors: Juliana Mara
authors: JM
authors: Serpeloni
authors: Patrícia Alves Ponte
authors: PA
authors: Monteiro
authors: Elder Francisco
authors: EF
authors: Latorraca
authors: Ricardo Santos
authors: RS
authors: de Oliveira
authors: Lusânia Maria Greggi
authors: LM
authors: Antunes
authors: Solange Cristina
authors: SC
authors: Garcia
authors: Fernando
authors: F
authors: Barbosa
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D020552:Comet Assay; D004032:Diet; D008297:Male; D008767:Methylmercury Compounds / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D013020:South America; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D008767:Methylmercury Compounds; D014874:Water Pollutants, Chemical