摘要目的 通过观察低硒条件下T-2毒素中毒大鼠血清丙二醛(MDA)的变化以及关节软骨4-羟基壬烯醛(4-HNE)和8-羟基鸟苷(8-OHdG)的表达水平,探讨低硒条件下T-2毒素中毒对大鼠关节软骨的氧化损伤作用.方法 32只雄性健康SD大鼠按体质量采用随机数字表法分为2组,每组16只.常规饲料组给予硒含量为101.5 μg/kg饮食,低硒饲料组给予硒含量为1.1 μg/kg饮食.30 d后,将常规饲料组分为对照组和T-2组,低硒饲料组分为低硒组和低硒+ T-2毒素组,每组8只大鼠.T-2组和低硒+T-2毒素组给予T-2毒素(100mg-1·kg-1·d-1)灌胃饲养.30 d后处死大鼠,取左侧膝关节,以HE和番红O-固绿染色,光镜下观察大鼠膝关节软骨病理学改变;免疫组织化学方法检测大鼠关节软骨细胞8-OHdG和4-HNE的表达水平;并用硫代巴比妥酸法检测大鼠血清丙二醛(MDA)含量.结果 光镜下低硒+T-2毒素组关节软骨深层可见片状坏死,软骨细胞死亡变为红染的“细胞影子”,或红染的无结构区域,番红-固绿着色显著减少.低硒+ T-2毒素组8-OHdG和4-HNE阳性表达率[(62.61±10.97)％、(75.03±7.92)％]明显高于对照组[(3.41±2.48)％、(2.28±1.74)％,F=16.24,18.61,P均＜0.05)].各组血清MDA含量比较,差异有统计学意义(F=4.32,P＜0.05),其中低硒组、T-2毒素组血清MDA含量[(2.803±0.163)、(2.890±0.453) μmol/L]明显高于对照组[(1.873±0.475)μmol/L,P均＜0.05],低硒+T-2毒素组血清MDA含量[(3.521±0.292)μmol/L]明显高于低硒组和对照组(P均＜ 0.05).结论 低硒条件下T-2毒素中毒引起大鼠关节软骨过氧化产物标志物升高.低硒与T-2毒素中毒的大鼠软骨破坏及其软骨细胞死亡与氧化损伤有关.

abstractsObjective To study the change of rats serum malondialdehyde (MDA) and the expression levels of 4-hydroxy acid nonene (4-HNE) and 8-hydroxy uridine (8-OHdG) of articular cartilage under low selenium (Se) and T-2 toxin poisoning,to explore oxidative damage of articular cartilage in rats.Methods Thirtytwo healthy male SD rats were divided into two groups by weight which were normal diet group and Se-deficiency group,16 rats in each group.Rats in normal diet group was fed with selenium 101.5 μg/kg diet,and rats in Sedeficiency group was fed with selenium 1.1 μg/kg diet for 30 d.Normal diet group was divided into control group and T-2 toxin group,and low selenium diet group was randomly divided into Se-deficiency group and Se-deficiency plus T-2 toxin group,8 rats in each group.After that,rats in T-2 toxin and Se-deficiency plus T-2 toxin groups were administrated intragastrically with T-2 toxin (100 mg/kg) everyday for 30 d.Rats were put to death,the left knee was taken and stained with hematoxylin-eosin and Safranin-Fast green,pathological changes of rat's knee joint cartilage were observed under light microscopy,expression levels of 8-OHdG and 4-HNE in rat's articular cartilage cells were determined by immunohistochemical method and rat's MDA content was determined by glucosinolates barbituric acid method.Results Chondronecrosis in deep zone of articular cartilage of knee joint stained with hematoxylin-eosin was seen in Se-deficient plus T-2 toxin diet group under light microscope.Significantly less Safranin-Fast green staining was observed in the cartilage of knee joints in the Se-deficient plus T-2 toxin diet group compared to the control group.Compared with control group [(3.41 ± 2.48)％,(2.28 ± 1.74)％],8-OHdG and 4-HNE in Se-deficient plus T-2 toxin group [(62.61 + 10.97)％,(75.03 ± 7.92) ％] positive expression rate increased significantly (F =16.24,18.61,all P ＜ 0.05).Comparison of serum MDA content in each group,the difference was statistically significant (F =4.32,P ＜ 0.05).The Se-deficiency group [(2.803 ± 0.163) μmol/L] was compared with control group [(1.873 ± 0.475) μmol/L] that the contents of serum MDA were increased.The T-2 toxin group [(2.890 ± 0.453) μmol/L] was compared with control group [(1.873 ± 0.475) μmol/L] that the content of serum MDA was increased (P ＜ 0.05).The Se-deficiency plus T-2 toxin group [(3.521 ± 0.292) μmol/L] was compared with Sedeficiency group and control group that the contents of serum MDA were increased (all P ＜ 0.05).Conclusions The marker of peroxidation products are increased in articular cartilage of SD rats under the condition of Sedeficiency and T-2 toxin poisoning.The cartilage damage and chondronecrosis due to Se-deficiency and T-2 toxin poisoning are related to oxidative damage.