小鼠肾集合管发育中主细胞的形态学变化及水通道蛋白-2和-3的表达

Morphology of principle cells and expression of aquaporin-2,-3 in collecting duct during mouse kidney development

目的观察小鼠肾集合管发育过程中主细胞的形态学变化及水通道蛋白(AQP)-2、-3的表达,探讨AQP-2、-3与小鼠肾集合管主细胞发育的关系及作用。方法应用透射电镜、免疫组织化学、免疫印迹技术并结合体视学方法,观察并检测胚龄16、18 d胎鼠及生后1、3、7、14、21 d仔鼠肾集合管发育过程中主细胞的形态学变化及AQP-2、-3的表达。结果小鼠胚龄18 d可见发育早期的主细胞。生后7～21d,主细胞形态结构发育基本完善。AQP-2于胚龄18 d表达于集合管主细胞游离面细胞膜和胞质内,生后1d其阳性表达逐渐增加,于生后21d达到高峰。AQP-3于胚龄16 d表达在主细胞的侧基底膜,生后1d达到较高水平。结论 AQP-2与AQP-3在肾发生发育中对水通透性的调节可能发挥了重要的作用,AQP-2的作用发生在出生后,AQP-3的作用主要发生在胚胎时期。

Objective To observe the morphological changes of principle cells and the expressions of aquaporin （AQP）-2 and AQP-3 in collecting duct during mouse kidney development, so to investigate their relationships and effects. Methods Transmission electron microscopy, immunohistochemistry, Western blotting and stereological methods were used to detect the expressions of AQP-2, AQP-3 and principle cells in mouse kidney of embryonic day 16, 18 and postnatal day 1,3,7,14 and 21. Results The collecting duct principle cells occurred at embryonic day 18. Morphological structures of principle cells were well-developed during postnatal day 7 to 21. AQP-2 was apparently noticed on the apical plasma membrane and in the cytoplasm of principle cells. The expression of AQP-2 increased at postnatal day 1 , and reached peak level at postnatal day 21. AQP-3 was expressed on the basolateral membrane of principle cells. The expressions of AQP-3 increased gradually and reached peak level at postnatal day 1. Conclusion AQP-2 and AQP-3 are very important for balance of water during development and maturation in mouse kidney,while AQP-2 is functioning after birth, but AQP-3 is functioning before birth.