实验性糖尿病对大鼠胸腺皮质上皮细胞的影响

THE INFLUENCE OF EXPERIMENTAL DIABETES ON THE EPITHELIAL CELLS IN RAT THYMIC CORTEX

目的 探讨糖尿病对大鼠胸腺皮质上皮细胞影响的形态学变化 ,了解其引起胸腺细胞凋亡及胸腺萎缩的可能机制。 方法 采用四氧嘧啶型糖尿病动物模型 ,电镜下观察了糖尿病大鼠胸腺皮质上皮细胞的超微结构变化。 结果 2型上皮细胞发生 4种变化 :1 内分泌功能紊乱样变 ,以大量变性的空泡与囊泡为特征 ;2 退化样变 ,以大量的变性分泌泡、髓样小体和粗大张力细丝束为特征 ;3 吞噬细胞样变 ,以大量的溶酶体样致密颗粒及吞噬的凋亡细胞与小体为特征 ;4 细胞凋亡样变 ,以细胞凋亡的早期形态学变化为特征。 3型上皮细胞发生两种变化 :1 退化样变 ,伴有大量分泌肽类激素样的致密颗粒群。 2 增生样变 ,在其胞体周伴有大量的胶原原纤维。此外 ,在胸腺皮质中还发现大量的胸腺细胞凋亡及胸腺细胞数量减少。 结论 糖尿病可导致大鼠胸腺皮质上皮细胞发生多样性的超微结构变化 ,可能是影响胸腺细胞发育 ,并导致其凋亡及胸腺萎缩的主要机制之一。

Objective To explore the morphologic changes of the epithelial cells in the thymic cortex in diabetes rats, and its possible mechanism of thymocyte apoptosis and thymus involution. Methods The ultrastructure changes of the epithelial cells in the thymic cortex in diabetes rats were observed under electron microscope. Results The type 2 epithelial cells had four kinds of the changes on ultrastructure:1 the endocrine disorder like changes with a large number of the degenerative cystic vacuoles;2 the degenerative like changes with lots of the abnormal secretory vacuoles and myelin like bodies and bulky tonofilament bundles; 3 the phagocyte like changes with a great number of the dense lysosome like granulae and the phagocytosed apoptotic cells and bodies; 4 the apoptosis like changes with the early morphologic changes of apoptosis. The type 3 epithelial cells had two kinds of the changes on ultrastructure:1 degenerative like changes with groups of dense granulae which secrete peptide hormones;2 the proliferative like changes with numerous collage fibrils in the vicivity of their perikarya. In addition, a lot of the apoptotic thymocytes and the reduction of thymocyte number were found in thymic cortex.Conclusion The varied ultrastructure changes of the epithelial cells in rat thymic cortex could be induced by diabetes, which might be the one of major mechanisms on influencing the thymocyte development and causing the thymocyte apoptosis and thymus involution.\;[