Aguilera G, Kapur S, Feuillan P, Sunar-Akbasak B, Bathia A J
Section on Endocrine Physiology, Developmental Endocrinology Branch, National Institutes of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland.
Kidney Int. 1994 Oct;46(4):973-9. doi: 10.1038/ki.1994.356.
The changes in angiotensin II receptor subtypes, type 1 (AT1) and type 2 (AT2) binding, and AT1 mRNA levels during development were studied in the rat kidney using autoradiographic and in situ hybridization techniques. Autoradiographic analysis of 125I-[Sar1,Ile8]Ang II binding to slide-mounted kidney sections from 2 and 5 day-old rats discerned AT2 binding sites associated with advancing tubules and ampullae of the ureteric bud, and in the metanephric mass in the nephrogenic zone of the cortex. AT1 binding was present in the metanephric mass and immature glomeruli on days 2, 5 and 7 after birth. Differentiating and mature kidneys of 14-day, 21-day and 14-week old adult rats had solely AT1 receptor binding over glomeruli in renal cortex and in the inner stripe of the outer medulla. AT1 mRNA was expressed discretely as early as 2 days of age in the immature glomeruli and in a diffuse radiating pattern in the renal cortex. In the medulla, AT1 receptor mRNA expression appeared discretely on day 7 and reached peak levels on day 21 in the inner stripe of the outer medulla. The data indicate that AT1 receptor mRNA is developmentally regulated in rat kidney and its expression in the cortex precedes that of AT1 receptor ligand binding. The temporal pattern of expression of binding for both receptor subtypes suggests that while AT2 receptors may be involved in cell proliferation and early differentiation of the nephron, AT1 receptors have a dual role, early in nephron differentiation and later in development in renal function.
采用放射自显影和原位杂交技术，研究了大鼠肾脏发育过程中血管紧张素II受体1型（AT1）和2型（AT2）结合的变化以及AT1 mRNA水平。对2日龄和5日龄大鼠肾脏切片进行125I-[Sar1，Ile8]Ang II结合的放射自显影分析，发现AT2结合位点与输尿管芽的肾小管和壶腹的发育以及皮质肾发生区的后肾组织有关。出生后第2、5和7天，后肾组织和未成熟肾小球中存在AT1结合。14日龄、21日龄和14周龄成年大鼠的分化和成熟肾脏在肾皮质肾小球和外髓质内带仅存在AT1受体结合。AT1 mRNA早在2日龄时就在未成熟肾小球中离散表达，并在肾皮质呈弥漫性放射状分布。在髓质中，AT1受体mRNA表达在第7天离散出现，并在第21天在外髓质内带达到峰值水平。数据表明，AT1受体mRNA在大鼠肾脏中受到发育调控，其在皮质中的表达先于AT1受体配体结合。两种受体亚型结合表达的时间模式表明，虽然AT2受体可能参与肾单位的细胞增殖和早期分化，但AT1受体具有双重作用，在肾单位分化早期和后期发育中发挥作用。
