Ho M M, Barker S, Vinson G P
Department of Biochemistry, Faculty of Basic Medical Sciences, Queen Mary and Westfield College, London, UK.
J Endocrinol. 1994 Jun;141(3):459-66. doi: 10.1677/joe.0.1410459.
Previous studies using a mouse monoclonal antibody (IZAb) have identified inner zone-specific antigens (IZAg 1 and 2) in the rat adrenal cortex. The expression of IZAg1 is enhanced by dibutyryl-cyclic AMP or ACTH in vitro and by in vivo ACTH treatment. These studies also suggest that IZAg may be involved in steriogenesis in rat adrenals. Using sensitive detection methods, the distribution of IZAg in adrenals from other species and in other rat tissues was studied. Pig and rabbit adrenals expressed an IZAb-immunoreactive protein with molecular mass identical with that of IZAg1, but no immunoreactivity was detected in bovine, guinea-pig or mouse adrenals. In the rabbit adrenal, as in the rat, IZAb bound only to zonae fasciculata/reticularis cells. However, the whole adrenal cortex in the pig immunoreacted with IZAb. Although immunofluorescence was observed in human adrenal sections, predominantly in the zona reticularis, no significant immunoreactive protein band was detected by immunoblot analysis. Apart from the zonae fasciculata/reticularis in the adrenal gland, an IZAb-immunoreactive protein with a molecular mass of 26,000 Da, corresponding to IZAg1, was also found in rat hepatocytes, renal tubules, ovary (corpus luteum, interstitial cells, theca interna of mature follicles) and Leydig cells. The observations suggest that IZAg may be involved in the processes of biosynthesis, metabolism and/or excretion of steroid hormones.
此前使用小鼠单克隆抗体（IZAb）开展的研究已在大鼠肾上腺皮质中鉴定出内层带特异性抗原（IZAg 1和2）。体外实验中，二丁酰环磷腺苷或促肾上腺皮质激素（ACTH）以及体内ACTH治疗均可增强IZAg1的表达。这些研究还表明，IZAg可能参与大鼠肾上腺的类固醇生成过程。利用灵敏的检测方法，对IZAg在其他物种肾上腺及大鼠其他组织中的分布情况进行了研究。猪和兔的肾上腺表达一种与IZAg1分子量相同的IZAb免疫反应性蛋白，但在牛、豚鼠或小鼠的肾上腺中未检测到免疫反应性。与大鼠一样，在兔肾上腺中，IZAb仅与束状带/网状带细胞结合。然而，猪的整个肾上腺皮质均与IZAb发生免疫反应。虽然在人类肾上腺切片中观察到了免疫荧光，主要位于网状带，但免疫印迹分析未检测到明显的免疫反应性蛋白条带。除肾上腺的束状带/网状带外，在大鼠肝细胞、肾小管、卵巢（黄体、间质细胞、成熟卵泡的内膜细胞）和睾丸间质细胞中也发现了一种分子量为26000 Da、与IZAg1相对应的IZAb免疫反应性蛋白。这些观察结果表明，IZAg可能参与类固醇激素的生物合成、代谢和/或排泄过程。
