Mizuno K, Ojima M, Hashimoto S, Tani M, Niimura S, Kunii N, Yabe R, Watari H, Inagami T, Fukuchi S
Clin Sci (Lond). 1987 Jun;72(6):699-704. doi: 10.1042/cs0720699.
There is increasing evidence which suggests that the adrenal gland contains the renin-angiotensin cycle. The localization of renin has been reported to be mainly in the zona glomerulosa rather than the fasciculata medullary portion. In the present study we have investigated extracts from aldosteronomas (n = 3), which are believed to derive from the zona glomerulosa cells. In addition, we have attempted to characterize the biochemical properties of the adrenal renin. Sizable quantities of renin-like activity (32.0 +/- 7.7 ng of angiotensin I generated h-1 mg-1 of protein, mean +/- SEM) were detected in the extracts. This renin-like activity was inhibited by anti-renin antibody raised against pure renin (mean, 95% of the total renin-like activity), indicating that it was not due to the non-specific action of proteases such as cathepsin D. The optimum pH of the tissue renin-like enzyme was 6.0 for rat plasma substrate. Differences were found, however, in the molecular mass (36,000, 37,000, 44,000 and 48,000), binding to concanavalin A and isoelectric points (4.40, 4.68 and 5.00). These results confirm the existence of specific renin in aldosteronoma. Renin microheterogeneity could be evidence for local production of the enzyme.
越来越多的证据表明肾上腺中存在肾素-血管紧张素循环。据报道，肾素的定位主要在球状带而非束状带髓质部分。在本研究中，我们研究了醛固酮瘤（n = 3）的提取物，这些醛固酮瘤被认为源自球状带细胞。此外，我们试图描述肾上腺肾素的生化特性。在提取物中检测到相当数量的肾素样活性（每毫克蛋白质每小时产生32.0±7.7纳克血管紧张素I，平均值±标准误）。这种肾素样活性被针对纯肾素产生的抗肾素抗体抑制（平均为总肾素样活性的95%），表明它不是由于诸如组织蛋白酶D等蛋白酶的非特异性作用。对于大鼠血浆底物，组织肾素样酶的最适pH为6.0。然而，在分子量（36,000、37,000、44,000和48,000）、与伴刀豆球蛋白A的结合以及等电点（4.40、4.68和5.00）方面发现了差异。这些结果证实了醛固酮瘤中存在特异性肾素。肾素的微观异质性可能是该酶局部产生的证据。
