RESUMO
An attempt was made to clarify the association between zinc (Zn) and antioxidants due to Zn supplementation on lipid peroxidation occurring during Brachiaria decumbens intoxication. The concentration of Zn, copper, malondialdehyde (MDA), superoxide dismutase (SOD), and gluthathione peroxidase (GSH-Px) were determined in tissues. There was a gradual increment in the concentration of Zn and MDA in serum and hepatocytic SOD in groups given Zn + B decumbens. A decline in erythrocytic GSH-Px and SOD, and lower concentration of reduced glutathione in hepatocyte cytosols were also detected in these sheep. It is highly suggestive that Zn supplementation may depress antioxidant status and enhance lipid peroxidation during B decumbens intoxication.
Assuntos
Suplementos Nutricionais/efeitos adversos , Peroxidação de Lipídeos/efeitos dos fármacos , Intoxicação por Plantas/veterinária , Poaceae/intoxicação , Doenças dos Ovinos/metabolismo , Zinco/efeitos adversos , Ração Animal , Animais , Eritrócitos/efeitos dos fármacos , Glutationa/sangue , Glutationa/efeitos dos fármacos , Glutationa Peroxidase/sangue , Glutationa Peroxidase/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Malondialdeído/análise , Panicum/intoxicação , Intoxicação por Plantas/etiologia , Intoxicação por Plantas/metabolismo , Ovinos , Doenças dos Ovinos/etiologia , Superóxido Dismutase/sangue , Superóxido Dismutase/efeitos dos fármacos , Zinco/análiseRESUMO
The influence of copper (Cu) overload on hepatic lipid peroxidation and antioxidation defense capacity was studied by overloading rats with copper sulphate orally (500 mg Cu/kg bw) 5 d/w for 8 w. Malondialdehyde (MDA), Cu-Zn superoxide dismutase (SOD), and Se-glutathione peroxidase (GSH-Px) were measured in serum and liver homogenate at 2, 4 and 8 w of dosing. Liver Cu concentration and alanine aminotransferase (ALT) activity were also determined. As Cu loading progressed, there were multiparameter changes with significant ALT elevation, increased MDA concentrations in serum and liver homogenate, and dramatic declines of SOD and GSH-Px activities in erythrocytes and whole blood respectively, along with marked elevation of hepatic Cu in the Cu-dosed group. Excessive Cu accumulation in the liver depressed SOD and GSH-Px activities and resulted in high MDA in serum and liver homogenate due to the lipid peroxidation induced by the Cu overload.
Assuntos
Antídotos/toxicidade , Sulfato de Cobre/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Administração Oral , Alanina Transaminase/sangue , Animais , Antídotos/administração & dosagem , Sulfato de Cobre/administração & dosagem , Radicais Livres/metabolismo , Fígado/enzimologia , Malondialdeído/sangue , Malondialdeído/metabolismo , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismoRESUMO
Samples of Brachiaria decumbens collected from 5 farms representing the Peninsular Malaysia were subjected to selected trace mineral and phytate analyses to explain the pathogenesis of B decumbens intoxication. Concentrations of Cu, Zn, Fe and Mo were comparable to other grasses while that of phytate was low. The molar ratios of Cu:Zn, Cu:Mo, and Cu:Fe warrant that Cu deficiency is involved in the toxicity of B decumbens. This might aggravate the development of photosensitization of unpigmented or lightly pigmented areas of affected animals. The Zn:phytate ratio could predispose to Zn deficiency during intoxication.
