IN-SITU HYBRIDIZATION AND IMMUNOHISTOCHEMISTRY OF RENAL ANGIOTENSINOGEN IN NEONATAL AND ADULT-RAT KIDNEYS
IN-SITU HYBRIDIZATION AND IMMUNOHISTOCHEMISTRY OF RENAL ANGIOTENSINOGEN IN NEONATAL AND ADULT-RAT KIDNEYS
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DOI：
10.1007/bf00583388
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发表时间：
1995-08-01
影响因子：
3.6
通讯作者：
SERNIA, C
中科院分区：
文献类型：
--
作者：
DARBY, IA;SERNIA, C
最近的证据表明，局部肾素-血管紧张素系统在肾脏中起作用，它介导了血管紧张素II对肾小管的一些作用。本研究用免疫组织化学、免疫电子显微镜和非同位素杂交组织化学方法研究了血管紧张素Ⅱ形成的独特前体--血管紧张素原在大鼠体内的个体发生和肾脏分布。光镜下，血管紧张素原在皮质近曲小管有较强的染色，在外条带的直近端小管有较浅的染色。新生大鼠肾脏免疫染色最强，肾小球系膜细胞和髓质血管束也呈免疫阳性。妊娠晚期胚胎和新生儿肾脏血管紧张素原含量在孕18天出现，新生儿肾血管紧张素原含量达到高峰。生物素化寡核苷酸探针的非同位素杂交组织化学证实，血管紧张素原mRNA在肾皮质近曲小管中表达。电子显微镜免疫组织化学染色显示，成人肾脏近曲小管细胞的顶膜附近有相对较少的电子致密结构。在新生大鼠肾脏，血管紧张素原免疫组织化学染色遍布近端小管细胞，且明显强于成年大鼠肾脏。从胚胎第18天起，血管紧张素原出现在肾脏的近端小管、系膜细胞和血管构筑中，提示肾内血管紧张素II产生的多个潜在部位，并在妊娠晚期发生个体发育。
Recent evidence suggests that a local renin-angiotensin system is operational in the kidney and that it mediates some of the actions of angiotensin II on renal tubules. In this study the ontogeny and renal distribution of the unique precursor to angiotensin II formation, angiotensinogen, was investigated in rats by use of immunohistochemistry, immune-electron microscopy and non-isotopic hybridization histochemistry. At the light-microscopic level, intense staining for angiotensinogen was found in the proximal convoluted tubules of the cortex, with lighter staining in the straight proximal tubules of the outer stripe. The strongest immunostaining was found in the kidneys of neonatal rats, where glomerular mesangial cells and medullary vascular bundles were also immunopositive. The angiotensinogen content of the kidneys in late gestation embryos and neonates showed the presence of angiotensinogen by day E18 and a peak content in the neonate. Non-isotopic hybridization histochemistry with biotinylated oligodeoxynucleotide probes confirmed the presence of angiotensinogen mRNA expression in the proximal convoluted tubules of the renal cortex. Electron-microscopic immunohistochemistry showed staining of relatively few electron-dense structures close to the apical membrane of proximal convoluted tubule cells in the adult kidney. In the neonatal rat kidney, angiotensinogen immunostaining at the electron-microscopic level was found throughout the proximal tubule cells and was markedly stronger than that seen in adult kidney. The presence of angiotensinogen, from embryonic day 18, in the proximal tubules, mesangial cells and vasculature of the kidney suggests multiple potential sites of intrarenal angiotensin II generation with an ontogeny in late gestation.