| Fumonisins are a group of discovered mycotoxins which are mainly produced by Fusarium moniliforme, as well as Fusarium verticillioides and they occur predominantely in maize and maizebased feeds. The contamination of feedstuffs with mycotoxins causes great economic losses, and results in a serious threat to the health and productivity of animals. It is reported that FB1 can cause damage on a variety of animals, equine leucoencephalomalacia, porcine pulmonary oedema, liver and kidney carcinoma in mice. The mechanisms of FB1 inducing pulmonary edema are poorly reported. This study has investigated the toxicity of FB1 on weaned piglets and porcine endothelial cells in vivo and vitro, to explore the mechanisms of pulmonary edema. The main research contents and results are as follows:1. Twelve pigs were fed with prepared food containing FB1 for 1 month to observe its pathological lesions and poisoning mechanism. The results showed that the levels of leukocytes in blood increased significantly, and the concentrations of 8-OXO-7,8-dihydroguanine(8-oxo-dG), reactive oxygen species(ROS), malondialdehyde(MDA), thioredoxin(TRX) content and glutathione peroxidase(GSH-Px) activity were increased, the Superoxide dismutase(SOD) activity decreased, with FB1 concentrations increasing. The concentrations of IL-2, IL-6, TNF-a and IFN-? were increased, IL-8 levels were not changed much with the FB1 concentrations increasing. These dates showed it had a marked pathological changes in pulmonary edema and serius glomerulonephritis, Serious granular degeneration, a small necrosis of liver, as well as granular degeneration of cardiac. Tunel assay showed that spleen cell apoptosis increased by FB1. P53 expression levels in the liver and spleen were significantly higher than those of the control group, With the detection of the P53, Bcl-xl and Bax expression-changes in heart, liver, spleen and lung by Real-time quantitative fluorescence PCR. This indicates that FB1 has significant toxicity in lung, kidney, liver and spleen.2.In this study, porcine endothelial cells were treated with FB1(0.25-2.0?g/ml) in 24 hours to observe its morphology changes, the activities of glutathione peroxidase(GSH-Px), 8-OXO-7,8-dihydroguanine(8-oxo-dG) and thioredoxin(TRX) content, P53, Bcl-xl and Bax expression changes, and to further explore the cells damage mechanisms of FB1.The results showed that marked morphological had a lot of changes and increased the rate of death of porcine endothelial cells with the FB1 concentrations increasing. Compared with the control group, with the increasing concentrations of FB1, TRX contents significantly decreased, the activities of GSH-Px has declined, and the contents of 8-oxo-dG in 0.5?g/ml and 1.0?g/ml FB1 was significantly increased. These data suggested that FB1 could induce oxidative stress, and resulted in obvious damage even death of cells with its increasing concentrations. Apoptosis related genes mRNA expression was detected by Real-time quantitative fluorescence PCR, which showed that, compared with the control group, the P53 mRNA expression was significantly increased, the expression of Bcl-xL mRNA significantly decreased, and the ratio of Bcl-xl/Bax decreased with the increasing FB1 concentrations. These might be one of reasons that FB1 induced the exudate in alveolar and renal cysts. |
PDF Full Text Request