Ho M M, Vinson G P
Department of Biochemistry, Queen Mary and Westfield College, London, U.K.
J Endocrinol. 1993 Nov;139(2):301-6. doi: 10.1677/joe.0.1390301.
It is now known that in the rat there are two distinct species of cytochrome P450(11 beta/18), namely aldosterone synthase and 11 beta-hydroxylase. Whereas aldosterone synthase is located exclusively in the zona glomerulosa, the zonal distribution and site of production of 11 beta-hydroxylase is not entirely clear. In the present study we examined the zonal expression of 11 beta-hydroxylase mRNA in adrenals from control rats and animals subjected to ACTH treatment and dietary sodium restriction using a non-isotopic in-situ hybridization technique. The results were compared with those obtained using an inner zone specific antigenic (IZAg) marker to give unequivocal identification of the adrenocortical cell types. 11 beta-Hydroxylase mRNA was clearly shown to be expressed in the inner zones of the control rat adrenal cortex, and none was detected in the zona glomerulosa and medulla. The message was more abundant in the outer zona fasciculata. A similar pattern of distribution of 11 beta-hydroxylase mRNA was observed in adrenals from rats subjected to dietary sodium restriction, although the width of the negatively staining layer of zona glomerulosa was significantly increased. In rats treated with 100 micrograms ACTH for 1 day, the number of cells expressing 11 beta-hydroxylase mRNA was increased, especially in the zona reticularis. With continued ACTH treatment, 11 beta-hydroxylase mRNA was found in the region of the zona glomerulosa, and after 3 and 5 days of ACTH treatment cells expressing 11 beta-hydroxylase mRNA extended to the connective tissue capsule. At this time there was a significant reduction in the total expression of the message compared with the controls.(ABSTRACT TRUNCATED AT 250 WORDS)
现已明确，在大鼠体内存在两种不同的细胞色素P450(11β/18)，即醛固酮合成酶和11β-羟化酶。醛固酮合成酶仅位于球状带，而11β-羟化酶的区域分布和产生部位尚不完全清楚。在本研究中，我们使用非同位素原位杂交技术，检测了对照大鼠以及接受促肾上腺皮质激素（ACTH）治疗和饮食限钠处理的动物肾上腺中11β-羟化酶mRNA的区域表达情况。将结果与使用内层区域特异性抗原（IZAg）标记物获得的结果进行比较，以明确鉴定肾上腺皮质细胞类型。结果清楚显示，11β-羟化酶mRNA在对照大鼠肾上腺皮质的内层区域表达，而在球状带和髓质中未检测到。该信息在束状带外层更为丰富。在饮食限钠的大鼠肾上腺中观察到11β-羟化酶mRNA的类似分布模式，尽管球状带负染色层的宽度显著增加。在用100微克ACTH治疗1天的大鼠中，表达11β-羟化酶mRNA的细胞数量增加，尤其是在网状带。随着ACTH持续治疗，在球状带区域发现了11β-羟化酶mRNA，在ACTH治疗3天和5天后，表达11β-羟化酶mRNA的细胞延伸至结缔组织被膜。此时，与对照组相比，该信息的总表达量显著降低。（摘要截短于250字）
