Marsigliante S, Acierno R, Maffia M, Muscella A, Vinson G P, Storelli C
Dipartimento di Biologia, Università di Lecce, Italy.
J Endocrinol. 1997 Aug;154(2):193-200. doi: 10.1677/joe.0.1540193.
The monoclonal antibody 6313/G2 raised against the mammalian type I (AT1) angiotensin II (Ang II) receptor (Ang II-R) also recognises a component in teleost (eel) tissue preparations that binds radiolabelled Ang II, and has an isoelectric point (pI) of 6.5 and molecular mass of 75 kDa. Immunohistochemical analysis using this antibody showed specific binding sites in eel intestine, kidney, gill and liver sections. The same antibody was used here to evaluate the presence and distribution of Ang II-R in target tissues of the Antarctic teleost icefish (Chionodraco hamatus). Immunocytochemistry of intestine and gill sections showed that the antibody bound to uniformly distributed intracellular sites and cell surface membranes in absorptive cells in the intestine and chloride and pavement cells in the gills. It also stained endothelium and both the longitudinal and circular layers of smooth muscle cells in the intestine. In the kidney, only the tubules in the trunk stained positively while the head (atubular part of the kidney) was negative. In kidney tubules, in contrast with other tissues, the receptor was most concentrated in the cytoplasm underlying the basolateral membranes, with somewhat weaker staining beneath the apical cell membrane. Immunoblotting identified a single component from trunk kidney preparations that focused at pI 5.9 in isoelectric focusing gels and showed a molecular mass of 75 kDa in SDS-polyacrylamide gels. The data suggest that, as in other teleosts, Ang II has a physiological role in the icefish.
针对哺乳动物I型（AT1）血管紧张素II（Ang II）受体（Ang II-R）产生的单克隆抗体6313/G2也能识别硬骨鱼（鳗鱼）组织制剂中与放射性标记的Ang II结合的一种成分，其等电点（pI）为6.5，分子量为75 kDa。使用该抗体进行的免疫组织化学分析显示，在鳗鱼的肠、肾、鳃和肝切片中有特异性结合位点。本文使用相同的抗体来评估南极硬骨鱼冰鱼（Chionodraco hamatus）靶组织中Ang II-R的存在和分布。肠和鳃切片的免疫细胞化学显示，该抗体与肠中吸收细胞以及鳃中氯化物细胞和扁平细胞内均匀分布的细胞内位点和细胞表面膜结合。它还对肠中的内皮以及平滑肌细胞的纵层和环层进行了染色。在肾脏中，只有躯干部分的肾小管呈阳性染色，而头部（肾脏的无肾小管部分）为阴性。与其他组织不同，在肾小管中，受体最集中在基底外侧膜下方的细胞质中，在顶端细胞膜下方的染色稍弱。免疫印迹法从躯干肾脏制剂中鉴定出一种单一成分，该成分在等电聚焦凝胶中的聚焦点为pI 5.9，在SDS-聚丙烯酰胺凝胶中的分子量为75 kDa。数据表明，与其他硬骨鱼一样，Ang II在冰鱼中具有生理作用。
