Rebuffat P, Rocco S, Andreis P G, Neri G, Nowak K W, Peters J, Opocher G, Mazzocchi G, Mantero F, Nussdorfer G G
Department of Anatomy, University of Padua, Italy.
J Steroid Biochem Mol Biol. 1995 Aug;54(3-4):155-62. doi: 10.1016/0960-0760(95)00127-l.
Heterozygous female transgenic rats for the murine Ren-2 gene (TGR) display a high blood pressure, together with a low kidney and high adrenal renin content. The effects of prolonged sodium restriction on the morphology and secretory activity of adrenal zona glomerulosa (ZG) of TGR and their age- and sex-matched Sprague-Dawley control rats (SDR) were investigated. Under basal conditions, TGR had a moderately hypertrophic ZG, that showed a significantly higher secretion of 18-hydroxylated (18OH) steroids: 18-hydroxy-11-deoxycorticosterone (18OH-DOC), 18-hydroxycorticosterone (18OH-B) and aldosterone (ALDO); ZG cells of TGR showed angiotensin II (AII)-binding site concentrations and ALDO secretory responses to AII similar to those of SDR ZG cells. Prolonged sodium restriction increased plasma ALDO level in both SDR and TGR, and significantly raised the volume of ZG. ZG hypertrophy was due to the increase in both the number and average volume of its parenchymal cells. The secretion of 18OH-steroids was markedly enhanced in both groups of rats; however, in TGR this rise was exclusively due to increases of 18OH-DOC and 18OH-B, while in SDR also ALDO production was enhanced. The yield of non-18OH-steroids was not affected. 11-Dehydrocorticosterone production was not changed in SDR, but doubled in TGR. ZG cells of sodium-restricted SDR and TGR displayed similar increases in their AII-binding site concentration and ALDO secretory response to AII. In conclusion, our present findings confirm that TGR possess a hypertrophic ZG and an elevated secretory capacity o 18OH-steroids, but show only slight differences in ZG and ZG-cell responses to prolonged sodium deprivation.
携带鼠肾素-2基因的杂合子雌性转基因大鼠（TGR）表现出高血压，同时肾脏肾素含量低而肾上腺肾素含量高。研究了长期限钠对TGR及其年龄和性别匹配的Sprague-Dawley对照大鼠（SDR）肾上腺球状带（ZG）形态和分泌活性的影响。在基础条件下，TGR的ZG中度肥大，其18-羟基化（18OH）类固醇的分泌显著增加：18-羟基-11-脱氧皮质酮（18OH-DOC）、18-羟基皮质酮（18OH-B）和醛固酮（ALDO）；TGR的ZG细胞显示血管紧张素II（AII）结合位点浓度以及对AII的ALDO分泌反应与SDR的ZG细胞相似。长期限钠使SDR和TGR的血浆ALDO水平均升高，并显著增加了ZG的体积。ZG肥大是由于其实质细胞数量和平均体积增加所致。两组大鼠中18OH类固醇的分泌均显著增强；然而，在TGR中，这种升高完全是由于18OH-DOC和18OH-B的增加，而在SDR中，ALDO的产生也增加。非18OH类固醇的产量不受影响。11-脱氢皮质酮的产生在SDR中未改变，但在TGR中增加了一倍。限钠的SDR和TGR的ZG细胞在其AII结合位点浓度和对AII的ALDO分泌反应方面显示出相似的增加。总之，我们目前的研究结果证实，TGR具有肥大的ZG和升高的18OH类固醇分泌能力，但在ZG和ZG细胞对长期钠缺乏的反应中仅显示出轻微差异。
