Şimşek Nejdet, Altunkaynak Berrrin Z, Ünal Deniz, Can Serpil, Malkoç Ismail, Ünal Bünyami
Atatürk University, Faculty of Veterinary Medicine, Department of Histology and Embryology, Erzurum, Turkey.
Atatürk University, Faculty of Medicine, Department of Histology and Embryology, Erzurum, Turkey.
Eurasian J Med. 2009 Aug;41(2):84-90.
To describe the morphometric and ultra-structural features of the kidney in fetal (20-day-old), newborn (7-day-old) and adult (180-day-old) rats.
Kidneys from all animals were excised, fixed in 3% glutaraldehyde in 0.1 M phosphate buffer, post-fixed in 1% phosphate-buffered osmium tetroxide, and examined by stereological and light and electron microscopic methods.
Fetal kidneys displayed kidney corpuscles, glomeruli, and proximal and collective tubules at multiple developmental stages. Glomeruli in the outer surfaces of the kidney were less mature than those in the inner surface. Kidney corpuscles were made up of parietal cells and podocytes without feet. Kidneys from newborn rats were almost completely developed, while kidneys in adult rats were fully developed. Under stereological examination, the percent volume of cortex in fetal kidneys (86.19%) was higher than in newborn (53.77%) or adult rats (76.78%). Compared to both newborn and fetal rats, adult rats displayed the highest total volumes of distal and proximal tubules, but lower mean glomerular or Bowman's capsule volumes. On the other hand, the total number of glomeruli was increased in adult rats (32,600) as compared to newborn (17,896) and fetal (11,650) rats.
These data suggest that development of metanephric kidneys is not yet complete by gestational day 20, but is almost complete at postnatal week one. Furthermore, the developmental stage of the kidney, as determined by stereology, correlates well with the age of the rat.
描述胎龄20天的胎儿、7日龄的新生大鼠和180日龄的成年大鼠肾脏的形态测量学和超微结构特征。
切除所有动物的肾脏，用0.1M磷酸盐缓冲液配制的3%戊二醛固定，再用1%磷酸盐缓冲四氧化锇后固定，采用体视学、光镜和电镜方法进行检查。
胎儿肾脏在多个发育阶段呈现肾小球、肾小囊以及近端和集合小管。肾脏外表面的肾小球比内表面的成熟度低。肾小囊由壁层细胞和无足突的足细胞组成。新生大鼠的肾脏几乎完全发育，而成年大鼠的肾脏已完全发育。在体视学检查中，胎儿肾脏皮质的体积百分比（86.19%）高于新生大鼠（53.77%）或成年大鼠（76.78%）。与新生大鼠和胎儿大鼠相比，成年大鼠的远端和近端小管总体积最大，但肾小球或鲍曼囊的平均体积较小。另一方面，成年大鼠的肾小球总数（32,600个）比新生大鼠（17,896个）和胎儿大鼠（11,650个）有所增加。
这些数据表明，后肾在妊娠第20天时发育尚未完成，但在出生后第一周时几乎已发育完成。此外，通过体视学确定的肾脏发育阶段与大鼠年龄密切相关。
