Minuth Will W
Institute of Anatomy, University of Regensburg, Regensburg D-93053, Germany.
Int J Nephrol. 2025 Mar 20;2025:7571982. doi: 10.1155/ijne/7571982. eCollection 2025.
The experiences with preterm and low birth weight babies indicate a special vulnerability of their kidneys, since different kinds of noxae can evoke the termination of nephron formation. This leads to oligonephropathy, which is associated with serious consequences for health in the later stages of life. While the clinical aspects have been intensely investigated, only few pathological data point to the initial traces left by the noxae. Up to this date, only the reduction in the width of the nephrogenic zone (NZ) and the lack of here occurring basophilic S-shaped bodies were reported. The relationship between the arising nephron and its structural neighbors changes throughout the developmental progress. Locally, this determines the vertical width of the NZ reflected by the radial expansion of both the parenchyma and the interstitium. Since information about the origin, the site, and the involved structures is not available, the related microanatomical features were recorded. The data reveal that the renal vesicles, comma-shaped bodies, and S-shaped bodies are unequally distributed in the NZ. Due to their progressive sizes, it has an influence on the local vertical width of the NZ. This parameter is registered as the distance between the inner side of the renal capsule and the proximal pole of the respective stage of the nephron anlage. The vertical width can be further subdivided: the constant height of the district of progenitor cell recruitment and the variable height of the area of nephron shaping. Exclusively here, the radial expansion of the shaping nephron stages can be noticed. It starts at the section border between the head and the conus of the related collecting duct ampulla by positioning the primitive renal vesicle. While the respective proximal pole stays mounted next to the connecting tubule of a previously developed nephron, the distal pole sticks between the head and the conus at the CD ampulla for linking the future connecting tubule. This causes that henceforth the medial aspect of the extending renal vesicle, comma-shaped body, or S-shaped body stages radially expands in close proximity to the elongating conus of the CD ampulla. Between the arising nephron stages and the elongating conus of the CD ampulla, a linked radial expansion occurs. This new finding is essential to identify the extent of targeting of noxae that subsequently leads to a reduction in the width of the NZ.
早产和低体重儿的经历表明其肾脏具有特殊的脆弱性，因为不同类型的有害物质可导致肾单位形成终止。这会导致肾发育不全，在生命后期对健康产生严重影响。虽然临床方面已得到深入研究，但只有少数病理数据指向有害物质留下的初始痕迹。截至目前，仅报道了肾发生区（NZ）宽度减小以及此处缺乏嗜碱性S形小体。在整个发育过程中，新生肾单位与其结构邻域之间的关系不断变化。在局部，这决定了由实质和间质的径向扩张所反映的NZ的垂直宽度。由于关于起源、部位和涉及结构的信息不可用，因此记录了相关的微观解剖特征。数据显示，肾小囊、逗号形小体和S形小体在NZ中分布不均。由于它们逐渐增大的尺寸，对NZ的局部垂直宽度有影响。该参数记录为肾被膜内侧与肾单位原基相应阶段近端极之间的距离。垂直宽度可进一步细分：祖细胞募集区的恒定高度和肾单位塑形区的可变高度。仅在此处，可以注意到塑形肾单位阶段的径向扩张。它通过定位原始肾小囊，从相关集合管壶腹头部和圆锥部之间的截面边界开始。当各自的近端极紧邻先前发育的肾单位的连接小管时，远端极则位于集合管壶腹头部和圆锥部之间，以连接未来的连接小管。这导致此后延伸的肾小囊、逗号形小体或S形小体阶段的内侧在紧邻集合管壶腹伸长的圆锥部处径向扩张。在新生肾单位阶段和集合管壶腹伸长的圆锥部之间，发生相关的径向扩张。这一新发现对于确定随后导致NZ宽度减小的有害物质靶向范围至关重要。
