Metabolism and mechanism of articular chondrocytes in young Wistar rats exposed to deoxynivalenol

Objective To examine the expression of collagen type Ⅱ,inducible nitric oxide synthase(iNOS),and matrix metalloproteinase(MMP-13) in articular chondrocytes induced by deoxynivalenol(DON).Methods The young healthy Wistar rats were divided into three groups:normal control,low and high-dosage of DON treatment groups.DON saline solution was injected into stomach of the rat on alternative day.The levels of collagen type Ⅱ,iNOS,MMP-13,and deoxypyridinoline(DPD) were determined by immunohistochemical technique,enzym-linked immunosorbent assay,and transmission electron microscope 80 days after the treatments.Results The content of collagen Ⅱ was 7.43%±1.12%,4.79%±0.96%,and 2.82%±0.68% for the control,low dose DON,and high dose DON group,respectively,with significant differences among the groups(P < 0.05 for all).The level of iNOS and MMP-13 had significant differences among the 3 groups(P < 0.05 for all),with higher levels in low and high-dosage of DON treatment groups compared to that of the control.The level of DPD was increased.The transmission electron microscope observation revealed the damage of collagen network of articular cartilage.Conclusion DON could increase the expression of iNOS in articular cartilage cells and promote the anabolism of mitic oxide,the expression of MMP-13,and the degradation of articular cartilage matrix such as collagen type Ⅱ; all these processes induce the damage of articular cartilage.