Nephropathy and hepatopathy in weaned piglets provoked by natural ochratoxin A and involved mechanisms.

Ochratoxin A (OTA) contamination is a worldwide problem in pig industry. The objectives of the present study were to investigate the toxicity of natural OTA in weaned piglets and to further explore the underlying mechanisms. Totally, 36 crossbred ([Landrace × Yorkshire] × Duroc) piglets were randomly divided into 3 groups (three replicates per group, 4 piglets per replicate), and fed a basal diet (Con group) and basal diets added with 0.4 mg (OTA-L group) or 0.8 mg OTA/kg (OTA-H group), respectively for 42 days. The results showed that growth performance was significantly decreased (P<0.05) in OTA added groups compared with Con group. OTA concentration was relatively high in serum and OTA concentration in kidney was higher than in liver, respectively. AST, creatinine and urea in serum of OTA added groups were significantly increased (P<0.05), while glucose, total protein, albumin and globulin in serum of OTA added groups were significantly decreased (P<0.05) compared with Con group. Degenerative changes were observed in the epithelial cells of proximal tubules and in hepatocytes of OTA added groups. Antioxidant capacities in blood of OTA added groups and in kidney of OTA-H group were significantly decreased (P<0.05) compared with Con group. The mRNA expressions of bcl-2 were up-regulated, mRNA expressions of bax were down-regulated and the ratio of bcl-2 and bax was increased in kidney and liver of OTA added groups compared with Con group. In conclusion, OTA could reduce antioxidant capacity and suppress apoptosis in tissues and cause degenerative changes in the epithelial cells in proximal tubules and hepatic cells, which may have a negative effect on the growth performance of piglets.