Institute of Anatomy, Medical Faculty, University of Nis, Zorana Djindjica 81, Nis, 18000, Serbia.
Institute of Histology and Embryology, Medical Faculty, University of Nis, Nis, Serbia.
Pediatr Nephrol. 2018 May;33(5):817-825. doi: 10.1007/s00467-017-3874-2. Epub 2017 Dec 23.
Human fetal kidney development is a complex and stepwise process. The number, shape, size and distribution of glomeruli provide important information on kidney organization. The aim of this study was to quantify glomerular developing forms during human fetal kidney development using stereological methods.
Kidney tissue specimens of 40 human fetuses with gestational ages ranging from 9 to 40 weeks were analyzed. Specimens were divided into eight groups based on gestational age, each corresponding to 1 lunar month. Stereological methods were used at the light microscopy level to estimate volume, surface and numerical density of the glomerular developing forms.
During gestation, nephrogenesis continually advanced, and the number of nephrons increased. Volume, surface and numerical densities of vesicular forms and S-shaped bodies decreased gradually in parallel with gradual increases in estimated stereological parameters for vascularized glomeruli. Volume density and surface density of vascularized glomeruli increased gradually during fetal kidney development, and numerical density increased until the seventh lunar month. A relative decrease in vascularized glomeruli per unit volume of cortex occurred during the last 3 lunar months. Nephrogenesis began to taper off by 32 weeks and was completed by 36 weeks of gestation. The last sample in which we observed vesicles was from a fetus aged 32 weeks, and the last sample with S-shaped bodies was from a fetus aged 36 weeks.
The present study is one of few quantitative studies conducted on human kidney development. Knowledge of normal human kidney morphogenesis during development could be important for future medical practice. Events occurring during fetal life may have significant consequences later in life.
人类胎儿肾脏发育是一个复杂且逐步的过程。肾小球的数量、形状、大小和分布为肾脏组织提供了重要信息。本研究旨在使用体视学方法量化人胎儿肾脏发育过程中的肾小球发育形态。
分析了 40 个人类胎儿的肾脏组织标本，这些胎儿的胎龄从 9 周到 40 周不等。根据胎龄将标本分为 8 组，每组对应 1 个阴历月。在光学显微镜水平上使用体视学方法来估计肾小球发育形态的体积、表面积和数量密度。
在妊娠期间，肾发生不断进展，肾单位数量增加。随着血管化肾小球的估计体视学参数逐渐增加，泡状和 S 形小体的体积、表面积和数量密度逐渐降低。血管化肾小球的体积密度和表面积密度在胎儿肾脏发育过程中逐渐增加，数量密度增加到第七个月。单位皮质体积中血管化肾小球的相对数量在最后 3 个月减少。到 32 周时，肾发生开始减少，并在 36 周的妊娠时完成。我们观察到泡状结构的最后一个样本来自胎龄为 32 周的胎儿，而观察到 S 形小体的最后一个样本来自胎龄为 36 周的胎儿。
本研究是为数不多的对人类肾脏发育进行定量研究的研究之一。了解正常人类肾脏发育形态对未来的医疗实践可能很重要。胎儿期发生的事件可能对以后的生活产生重大影响。
