Measurement of plasma renin substrate by radioimmunoassay of angiotensin. I. Concentration in syndromes associated with steroid excess.
Measurement of plasma renin substrate by radioimmunoassay of angiotensin. I. Concentration in syndromes associated with steroid excess.
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DOI：
10.1210/jcem-37-1-110
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发表时间：
1973-07
期刊：
影响因子：
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通讯作者：
Lawrence R. Krakoff
中科院分区：
文献类型：
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作者：
Lawrence R. Krakoff
用放射免疫法测定正常人和激素过量综合征患者血浆肾素底物（PRS）和血浆肾素活性（PRA）。在患有库欣综合征、糖皮质激素治疗和口服避孕药或雌激素的受试者中，观察到血浆肾素底物显著升高。仅在原发性醛固酮增多症患者中，血浆肾素活性显著抑制。通过测定生理pH下血浆肾素-底物反应的Km来评估PRS升高的意义。该反应的表观Km为1000 ng血管紧张素I（PRS单位）。通过计算平均正常PRS浓度为1100 ng/ml时发生的反应速率，将测量的PRA校正为标准化PRA。结果表明，发生在库欣综合征或与糖皮质激素，口服避孕药，或雌激素给药的PRS升高足以显着提高血浆中的肾素底物反应。相反，糖皮质激素过量似乎不抑制血浆肾素活性，即使反应率增加PRS校正。
Plasma renin substrate (PRS) and plasma renin activity (PRA) were measured by radioimmunoassay of generated angiotension I in normal subjects and patients with steroid excess syndromes. In subjects with Cushing's syndrome, glucocorticosteroid therapy and oral contraceptive agents or estrogens, significant elevations of plasma renin substrate was observed. Only in subjects with primary aldosteronism was the plasma renin activity significantly supressed. The significance of elevations of PRS was assessed by determining the Km of the plasma renin-substrate reaction at physiologic pH. The apparent Km for the reaction was 1000 ng Angiotension I in PRS units. Correction of measured PRA to a standardized PRA was achieved by calculation of the reaction rate that would occur at the mean normal PRS concentration of 1100 ng/ml. Results indicate that elevations of PRS which occur in Cushing's syndrome or with administration of glucocorticoids, oral contraceptive agents, or estrogens are sufficient to significantly elevate the renin substrate reaction in plasma. In contrast, glucocorticoid excess appears not to suppress plasma renin activity even when reaction rates are corrected for increased PRS.