Frei N, Weissenberger J, Beck-Sickinger A G, Höfliger M, Weis J, Imboden H
Division of Neurobiology, Institute of Zoology, University of Berne, Baltzerstr. 6, CH-3012, Berne, Switzerland.
Regul Pept. 2001 Sep 15;101(1-3):149-55. doi: 10.1016/s0167-0115(01)00278-6.
Angiotensin II (Ang II), a major regulator of cardiovascular function and body fluid homeostasis, mediates its biological actions via two subtypes of G protein-coupled receptors, termed AT(1) and AT(2). The primary goal of this study was to raise monoclonal anti-peptide antibodies specific to angiotensin AT(1)- and AT(2)-receptor subtypes and to Ang II itself and using these monoclonal antibodies to determine the intraadrenal localization of AT(1) and AT(2) receptors and Ang II in male adult rats. Immunocytochemistry unambiguously demonstrates a regional colocalization of Ang II and angiotensin II receptors in the adrenal gland. The novel antibodies localized Ang II and the AT(1) receptors to the zona glomerulosa of the cortex and to the medulla whereas AT(2) receptors were limited to the medulla. The specificity of immunostaining was documented by pre-adsorption of the antibody with the immunogenic peptide. Our data underscore that AT(1) appears to mediate most of the physiological actions of Ang II in adrenal. Western blot analysis of rat adrenal protein extracts using AT(1) antibody showed a predominant 73-kDa band and a weaker 97-kDa immunoreactive band corresponding to glycosylated forms of the AT(1) receptor. Immunostaining with anti-AT(2) yielded one major immunoreactive band of 73-kDa size and one additional fainter band of 120 kDa. These antibodies may prove of value in unraveling the subcellular localization and intracellular effector pathways of AT(1) and AT(2).
血管紧张素II（Ang II）是心血管功能和体液稳态的主要调节因子，它通过两种G蛋白偶联受体亚型（称为AT(1)和AT(2)）介导其生物学作用。本研究的主要目的是制备针对血管紧张素AT(1)和AT(2)受体亚型以及Ang II本身的特异性单克隆抗肽抗体，并使用这些单克隆抗体确定成年雄性大鼠肾上腺内AT(1)和AT(2)受体以及Ang II的定位。免疫细胞化学明确显示肾上腺中Ang II和血管紧张素II受体存在区域共定位。新型抗体将Ang II和AT(1)受体定位于皮质的球状带和髓质，而AT(2)受体仅限于髓质。用免疫原性肽预先吸附抗体证明了免疫染色的特异性。我们的数据强调，AT(1)似乎介导了肾上腺中Ang II的大多数生理作用。使用AT(1)抗体对大鼠肾上腺蛋白提取物进行的蛋白质印迹分析显示，主要有一条73 kDa的条带和一条较弱的97 kDa免疫反应条带，对应于AT(1)受体的糖基化形式。用抗AT(2)进行免疫染色产生一条主要的73 kDa大小的免疫反应条带和一条额外较淡的120 kDa条带。这些抗体可能在阐明AT(1)和AT(2)的亚细胞定位和细胞内效应途径方面具有价值。
