Murakami K, Tsuchiya K, Naruse M, Naruse K, Demura H, Arai J, Nihei H
Department of Medicine, Kidney Center, Tokyo Women's Medical College, Japan.
Kidney Int Suppl. 1997 Dec;63:S208-10.
The present study was undertaken to clarify the mechanism of the regulation of nitric oxide synthase (NOS)-I in the macula densa of the kidney. We determined the changes in NOS-I immunoreactivity of the macula densa relevant to the changes in systemic blood pressure (BP) and the renin-angiotensin system. Rats received four different types of treatment, and kidney sections were immunohistochemically stained for renin, NOS-I, and NOS-III. Plasma renin activity (PRA) and angiotensin II (Ang II) concentration were determined by radioimmunoassay. In the low-salt group, PRA, plasma Ang II, and the number of renin and NOS-I positively stained areas in the juxtaglomerular apparatus (JGA) were all increased, while BP and NOS-III in the glomerular capillaries did not change. In the desoxycorticosterone acetate (DOCA)-salt group, in contrast to the elevation of BP, PRA, plasma Ang II, and all immunohistochemical parameters were decreased. In the Ang II infusion group, BP, plasma Ang II, and the number of NOS-I positive glomeruli were increased, while PRA and renin staining were decreased. Administration of Ang II type 1 receptor (AT-1) antagonist TCV-116 significantly increased PRA, plasma Ang II, and the number of renin-positive glomeruli. However, BP, and NOS-I and NOS-III staining did not show any difference. These results clearly suggest that NOS-I in the macula densa changes in parallel with plasma Ang II, but not renin or systemic BP.
本研究旨在阐明肾脏致密斑中一氧化氮合酶（NOS）-I的调节机制。我们确定了致密斑中NOS-I免疫反应性与全身血压（BP）和肾素-血管紧张素系统变化相关的改变。大鼠接受四种不同类型的处理，肾脏切片进行肾素、NOS-I和NOS-III的免疫组织化学染色。通过放射免疫测定法测定血浆肾素活性（PRA）和血管紧张素II（Ang II）浓度。在低盐组中，PRA、血浆Ang II以及肾小球旁器（JGA）中肾素和NOS-I阳性染色区域的数量均增加，而肾小球毛细血管中的BP和NOS-III未改变。在醋酸脱氧皮质酮（DOCA）-盐组中，与BP升高相反，PRA、血浆Ang II以及所有免疫组织化学参数均降低。在Ang II输注组中，BP、血浆Ang II以及NOS-I阳性肾小球的数量增加，而PRA和肾素染色降低。给予1型血管紧张素II受体（AT-1）拮抗剂TCV-116可显著增加PRA、血浆Ang II以及肾素阳性肾小球的数量。然而，BP以及NOS-I和NOS-III染色没有显示出任何差异。这些结果清楚地表明，致密斑中的NOS-I与血浆Ang II平行变化，而与肾素或全身BP无关。
