不同剂量T-2毒素对大鼠关节软骨损伤的形态学观察

Morphology damages of rat articular cartilage induced by different doses of T-2 toxin

目的观察不同剂量T-2毒素对大鼠关节软骨的损害程度，探讨低剂量T-2毒素与大鼠关节软骨损伤的关系。方法Wistar大鼠120只，体质量50～70g。按体质量将大鼠随机分为4组：T-2毒素0（对照）、100、200、300μg／kg组，每组30只。对照组食用常规颗粒料，T-2毒素组食用经T-2毒素（剂量分别为100、200、300txg／kg）染毒的颗粒料。喂养6个月后处死大鼠，取双侧膝关节，制备切片，光镜和电镜下观察大鼠关节软骨的损伤情况。结果光镜下，对照组大鼠关节软骨细胞群排列整齐，层次清晰，结构完好；100斗∥kg组关节软骨细胞排列紊乱；200μg／kg组关节软骨细胞出现变形、变性，细胞核固缩；300μg／kg组可见大面积的软骨细胞坏死，坏死部位细胞显著减少，呈现无细胞区，在坏死灶周围可见单个坏死软骨细胞．坏死细胞胞质红染、胞核浓缩、碎裂和溶解。扫描电镜下，对照组大鼠关节软骨细胞形态、结构良好，层次分明．排列整齐：100μg/kg组关节软骨表面明显粗糙；200μg／kg组软骨纤维凸起、断裂，呈片状剥脱；300μg/kg组关节面塌陷，出现大量窝状凹坑。透射电镜下，对照组大鼠软骨细胞胞质丰富，粗面内质网发达；100μg／kg组软骨细胞核染色质块状边集，核膜增厚，内质网空泡变性；200μg／kg组软骨细胞内质网扩张明显，蛋白潴留，细胞器溶解破裂；300μg／kg组软骨细胞细胞器大量溶解消失，膜结构破裂，基质溶解。结论在100～300μg／kg剂量范围内，T-2毒素致大鼠关节软骨损伤与剂量有关，染毒剂量越大，关节软骨损害越严重。

Objective To study the damage of rat articular cartilage induced by different doses of T-2 toxin, and to explore the relationship between mini-dose T-2 toxin and articular cartilage damage. Methods A total of 120 Wistar rats, weighing 50 - 70 g, were randomly divided into four groups according to their body weights： T-2 toxin group 0（control）, 100, 200, 300 μg/kg, 30 rats in each group. Animals in the control group were fed standard rat chow, and animals in the three T-2 toxin groups were fed T-2-toxin-contaminated chow（the dose was 100, 200, 300 μg/kg, respectively）. After 6 months, rats were euthanized by ether asphyxiation. The bilateral knee joints were collected and section prepared. The articular cartilage was examined by light and electronic microscope. Results Light microscope showed, the rat articular chondrocytes were clear and arranged orderliness in the control group. The rat articular chondrocytes were disarranged in 100 μg/kg T-2 toxin group. Degeneration and necrosis were found in 200 μg/kg group. Chondrocytes were shrunken with hypereosinophilia cytoplasm and fragmented pyknotie nuclei, extensive areas of chondrocyte loss and chondrocyte clones were visible in 300 μg/kg group. Scanning electronic micrograph （SEM） showed, the rat articular chondrocytes were clear, well formed and arranged tidy in the control group. The surface of articular cartilage was rough in 100 μg/kg group.Collagen fasciculi ruptured and stacked up in 200 μg/kg group. Presented a typical ＂articular dryness＂ phenomenon, the cartilage surface collapsed and many pits appeared in 300 μg/kg group. Transmission electronic microscope （TEM） showed that chondrocytes were abundant with cytoplasm, well-developed rough endoplasmic reticulum in the control group; agglomerate chromatin scattered along the karyotheca, nuclear membrane was thickening, with vacuolar degeneration of the endoplasmic reticulum in the 100 μg/kg group ; endoplasmic reticulum expended, with protein retention and organelles breaks in the 200 μg/kg group. A large number of chondrocytes lost organelles, the membrane structures disrupted and the cartilage matrix stromatolyzed in the 300 μg/kg group. Conclusions Within the range of 100 - 300μg/kg, T-2 toxin induces dose-related articular cartilage injury, the greater the dose, the more serious damage.