低甲和高甲大鼠肾单位远部细胞超微结构的变化——形态计量学研究

EFFECTS OF THYROID HORMONE ON THE ULTRASTRUCTURE OF DISTAL NEPHRON IN RAT——A MORPHOMETRIC STUDY

用甲状腺机能低下(低甲)和甲状腺机能亢进(高甲)动物模型,对大鼠肾皮质远端肾单位进行了电镜下细胞形态计量学分析。结果表明,低甲时远端肾单位的远端小管曲部细胞、远端小管直部细胞和集合小管主细胞的截面积(A)、侧基底面细胞质膜面密度(Sv)和周界长度[B(A)]、线粒体体密度(Vv)、及远端小管直部细胞和集合小管主细胞的游离面细胞质膜面密度和周界长度、集合小管直部细胞游离面微绒毛长度均明显下降。高甲时集合小管闰细胞的截面积和线粒体体密度增加。由此可见,甲状腺激素是影响远端肾单位细胞膜和线粒体形态结构的主要因素之一。

An ultrastructural analysis of distal nephron has been investigated using morphometric method for rats with hyperthyroidism and hypothyroidism. The cells analysed were distal convoluted tubule cells (DCT cells), distal straight tubule cells (DST cells), intercalated cells (I cells) and principal cells (P cells) of collecting duct. The cells were sampled from superficial cortex. The results revealed that in DCT, DST and P cells the profile area of cells, the surface density of plasma membrane (Sv), the boundary length of cell surface [B(A)], the volume density (Vv) of mitochondria, and the length of microvilli were significantly decreased in the rat with hypothyroidism. However, in the rat with hyperthyroidism there were an obvious increase of profile area of cell and Vv of mitochondria in I cells. The results suggest that thyroid hormone is an important factor for maintaining the normal cellular structure in the distal nephron. The morphometry shows that the changes of DCT, DST and P cells are distinct in the rat with hypothyroidism, and the ultrastructural changes of I cell are obvious in the rat with hyperthyroidism.