【摘要】 目的研究细胞内吞受体megalin和cubilin在胚胎发生发育小鼠肾的表达,及其与肾小管发生发育的相关性。方法采用免疫组织化学方法检测不同胚龄小鼠肾(每组5只)megalin和cubilin的表达。同时,结合透射电镜观察肾近端小管与细胞内吞功能相关的细胞器的发育变化。结果胚龄9.5d时,megalin和cubilin表达于中肾管及中肾小管上皮细胞游离面。胚龄11d至18d,两受体表达于输尿管芽上皮细胞游离面,在S小体期肾小管近腔面呈弱阳性表达,肾小管细胞内吞体及溶酶体少见,微绒毛稀疏。随着近髓肾单位细胞内吞体及微绒毛发育成熟,两受体表达局限于近端小管近腔面及刷状缘。结论megalin和cubilin在胚胎肾发生发育中,从表达在分化早期所有小管近腔面胞质,到局限于成熟期近端小管游离面刷状缘,提示两受体协同重吸收功能是随着近端小管上皮细胞的发育而逐渐形成的。更多还原

【Abstract】 Objective To investigate the expression of endocytic receptor megalin and cubilinin in the developing mouse kidneys,and the correlation between the expression and the development of the renal tubules. Methods Expression of megalin and cubilin in developing mouse kidneys was examined at different embryonic days(E) using immunohistochemistry.Meanwhile,the ultrastructure of developing proximal tubules related to endocytosis was observed at transimission electron microscope level. Results At E9.5,megalin and cubilin were co-expressed in apical plasma membrane of the mesonephric ducts and mesonephric tubules.From E11 to E18,in the metanephros,the expression of both receptors were seen at the free surface and apical plasma of uretic bud,but weakly in all renal tubules of S shaped body at early differentiatial stage.With the mature of proximal tubule development,they were both confined to the brush border and the apical plasma of the proximal tubules in juxtamedullary cortex.Conclusion The endocytic receptors,megalin and cubilin are expressed in apical part of nearly all renal tubule epithelia in early development,and confined to free surface of mature proximal tubules,suggesting that with the mature of proximal tubules,the two receptors are generally involved in collaborating to facilitate, the reabsorption of ultrafiltration.更多还原