ObjectiveTo observe the preventive effect of type Ⅱ collagen on experimental rat articular cartilage damage induced by T-2 toxin,to explore molecular biomarkers of articular cartilage damage and repair,and to provide a theoretical basis for control of articular cartilage damage.MethodsEighty Wistar rats were randomly divided into 4 groups according to their body weights:negative control,positive control,high-dose intervention,and low-dose intervention groups,20 rats in each group.Animals in negative control group were fed with standard rat chow,and animals in other three groups were fed with T-2-toxin-contaminated chow( 100 ng/kgfeed).Animals in negative and positive control groups drank distilled water,animals in high-dose intervention and low-dose intervention groups drank water containing type Ⅱ collagen(0.5,5.0 g/L,respectively).These rats were sacrificed after 3 and 5 months,respectively,and bilateral knee joints were collected.Histopathologic changes in hyaline cartilage were examined by light microscope,serum levels of type Ⅱ collagen carboxyl terminal peptide (CTX-Ⅱ ),cartilage oligomeric matrix protein (COMP) and urinary deoxypyridinoline (DPD) were determined by enzyme-linked immunosorbent assay(ELISA).ResultsHE staining showed,that the positive control articular chondrocytes were disarranged,deformated,degenerated,with necrosis and extensive areas of chondrocyte loss;but the two intervention groups only showed fibril formation and swelling and surface cartilage cells became round,flat cartilage cells decreased in number,and cartilage cells clustered and so on early pathological changes of osteoarthritis.At the ends of 3 month and 5 month experiment,the levels of serum CTX- Ⅱ in different groups were,negative control[(18.77 ± 4.61),(25.07 ± 9.17)μg/L],high-dose intervention[ (21.11 ± 5.02),(33.20 ± 9.74)μg/L ],low-dose intervention [ ( 19.87 ± 4.53 ),( 29.73 ± 9.32 ) μg/L ] and positive control [ ( 24.43 ± 5.23 ),( 39.17 ±10.49 ) μg/L ] ; the levels of serum COMP were,negative control group [ (5.43 ± 2.75 ),( 6.38 ± 2.23 ) μg/L ],highdose intervention group[ (17.27 ± 4.77),(20.32 ± 4.74)μg/L],low-dose intervention group[(20.13 ± 5.07),(19.44 ± 4.92)μg/L] and positive control group[ (21.37 ± 4.72),(24.52 ± 4.26)μg/L].At the end of 3 month,compared with negative control group,the level of serum CTX- Ⅱ in other three groups increased,but only positive control group increased significantly(P ＜ 0.05) ; at the end of 5 month,compared with negative control group,the level of serum CTX-Ⅱ in other three groups increased significantly,and the difference was statistically significant (all P ＜ 0.05),and the level of CTX-Ⅱ in the two intervention groups was significantly lower compared with that of positive control group(all P ＜ 0.05).Compared with negative control group,the level of serum COMP in other groups increased significantly at the end of 3 month (all P ＜ 0.05) and only the level of serum COMP in high-dose intervention group was significantly lower compared with that of positive control group(P ＜ 0.05).At the end of 5 month,compared with negative control group,the level of serum COMP in other three groups increased significantly,the difference were statistically significant (all P ＜ 0.05) ; the levels of serum COMP in the two intervention groups were significantly lower than that of positive control group(all P ＜ 0.05).At the ends of 3 month and 5 month,the content of urinary DPD in negative control group were[ (3.47 ± 2.20),(4.14 ± 1.06)μg/L],positive control group[ (4.09 ± 2.48),(4.33 ± 3.43)μg/L],high-dose intervention group[ (3.86 ± 2.31 ),(5.72 ± 3.89)μg/L] and low-dose intervention group[ (3.58 ± 2.77),(4.23 ± 2.90)μg/L].The difference between the 4 groups were not statistically significant (F =2.608,2.436,all P ＞ 0.05).ConclusionsType Ⅱ collagen could effectively reduce the level of serum CTX-Ⅱ and COMP in experimental rats and delay the process of articular cartilage damage induced by T-2 toxin.

ObjectiveTo study the impact of jogging mode on T-2 toxin-induced articular cartilage injury in rats,and to evaluate the role of movement in the development of bone and joint disease.MethodsA hundred Wistar rats were randomly divided into five groups:negative control group(free activities in the cage),positive control group(firee activities in the cage),high-regulation group(regular exercise,the treadmill speed of 24 m/min),lowregulation group (regular exercise,the treadmill speed of 12 m/min) and the random group(random exercise,the treadmill speed of 12 or 24 n/min).The negative control group was fed on commercial grain fodder and other groups were fed on grain fodder contaminated with T-2 toxin.At the end of 5,10 weeks,the histopathological changes of hyaline cartilage were detected by optical microscope,and the level of serum cartilage oligomeric matrix protein (COMP) was determined.ResultsArticular cartilage lesions in each experimental group was evident,presented as cartilage cell degeneration,necrosis,karyopyknosis deeply stained,cells arranged in disorder and cell proliferation,articular dryness,and so on.Compared with the positive control group,the cartilage surface cells of rats in the movement groups showed degeneration,necrosis and loss of cells obviously.The injury in high-regulation group was the most serious than that in other movement groups,with the surface and the middle layer lesions,and a large area of cartilage necrosis,and loss of matrix collagen; cartilage degeneration,polarity disappeared,cell proliferation-based disorder showed in random group.The pathological changes of rat articular cartilage damage worsened with the extension of experimental period.The serum levels of COMP at week 5 in experimental groups were higher than that of both the negative control group and the positive control group,and the difference was statistically significant (F =15.733,P ＜ 0.05 ); compared with negative control group [ (11.55 ± 0.89)μg/L],the COMP levels in high-regulation group,low-regulation group,random group[(13.95 ± 1.23),(14.96 ± 1.29),( 12.99 ± 1.43)μg/L] were significantly higher(all P ＜ 0.05); compared with the positive control group[(12.32 ± 1.38) μg/L],the COMP levels in high-regulation group and low-regulation group were significantly higher(all P ＜ 0.05) ; and compared between the exercise groups,the COMP levels in low-regulatinn group were higher than that of random group(P ＜ 0.05).At week 10,the changes were in the same trend as that of week 5,and the difference between groups was statistically significant (F =6.144,P ＜ 0.05) ; and compared with the negative control group [(10.59 ± 1.93)μg/L],the COMP levels in high-regulation group,low-regulation group,random group [ ( 13.72 ± 2.67 ),( 14.94 ± 1.06 ),( 13.21 ± 1.58 ) μg/L] were significantly higher(all P ＜ 0.05) ; compared with the positive control group[ (11.45 ± 0.12)μg/L],the COMP levels in low-regulation group were significantly higher (P＜0.05); but compared with the exercise groups,the difference were not statistically significant(all P＞0.05).ConclusionsHigh-intensity regular running and irregular intensity running can increase the articular cartilage damage,and injury of articular cartilage by low-intensity treadmill exercise is not significant.