Ultrastructural and biochemical observations on the metanephros of normal and cultured chick embryos
Ultrastructural and biochemical observations on the metanephros of normal and cultured chick embryos
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正常和培养鸡胚胎后肾的超微结构和生化观察
DOI：
10.1007/bf00315734
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
S. Kacew
中科院分区：
文献类型：
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作者：
R. Narbaitz;S. Kacew
对无壳培养或卵内分化的鸡胚后肾进行了比较电子显微镜研究。两种情况下的发育特征非常相似。到第 37 阶段（汉堡-汉密尔顿），后肾单位含有大量未成熟的肾单位；它们的肾小体呈新月形，由外层扁平细胞和内层立方细胞组成。在更高级的小体中，在这个阶段还发现内层已形成许多未发育的蒂，肾小球小动脉的中膜含有具有大量小电子致密颗粒的近肾小球细胞。在38阶段或更早的胚胎的后肾中，大量肾单位已完成分化；它们的圆形肾小体具有完全分化的足细胞，具有薄的叉指蒂，近曲小管具有许多顶端微绒毛、囊泡、空泡和管状内陷，表明吸收过程活跃。这些结果似乎表明，在培养物和卵发育胚胎中，后肾在第 38 阶段左右开始发挥作用。在正常胚胎的情况下，这一结论与之前的生理和生化测定一致。将 20 USP 甲状旁腺激素注射到 16 天大的鸡胚中，后肾中环 AMP 的浓度增加。这支持了激素对肾功能的调节从胚胎时期就开始的观点。
A comparative electron microscopical study was conducted on the metanephros from chick embryos differentiated either in shell-less culture or in ovo. Developmental characteristics were very similar in both cases. Up to stage 37 (Hamburger-Hamilton) the metanephros contained large numbers of immature nephrons; their renal corpuscles were crescent-shaped and consisted of an outer layer of flat cells and an inner one of cuboidal cells. In more advanced corpuscles also found at this stage the inner layer had formed numerous rudimentary pedicels and the tunica media of the glomerular arteriole contained juxta-glomerular cells with numerous, small, electron dense granules.In the metanephros from embryos at stage 38 or older, large numbers of nephrons had completed their differentiation; their rounded renal corpuscles had fully differentiated podocytes with thin interdigitating pedicels and the proximal convoluted tubules had numerous apical microvilli, vesicles, vacuoles and tubular invaginations indicating an active process of resorption. These results appear to indicate that both in culture and in ovo-developed embryos, the metanephri start to function around stage 38. In the case of normal embryos this conclusion agrees with previous physiological and biochemical determinations. The injection of 20 USP parathyroid hormone into 16-day old chick embryos produced an increase in the concentration of cyclic AMP in the metanephros. This favours the idea that the regulation of kidney function by the hormone begins during the embryonic period.