液体闪烁计数器检测血浆肾素活性及醛固酮

Establishment of Fluid Scintillation Counter Method for Measurement of Plasma Renin Activity and Aldosterone

目的建立使用液体闪烁计数器检测血浆肾素活性(PRA)及醛固酮(ALD)的方法及临床应用。方法应用竞争机制原理,血浆(或标准品溶液)中的醛固酮(ALD)或血管紧张素I(AI)以及加入的放射性免疫试剂125I-ALD或125I-AI,竞争性地与一定量的特异性抗体产生免疫反应。血浆(或标准品溶液)中ALD或AI则优先与特异性抗体结合,剩余的抗体再与放射性免疫试剂125I-ALD或125I-AI结合。用驴抗兔免疫分离试剂沉淀被抗体结合的125I-ALD或125I-AI。离心,取上清液,使用β-液体闪烁计数器,检测未被抗体结合的游离的125I-ALD或125I-AI的放射性强度。建立相应的标准曲线方程,求得血浆中ALD或AI的含量,计算肾素活性(PRA)及ALD/PRA比值。结果变异系数RSD(%)为6.18%～10.79%,AI、ALD的回收率分别为87.61%～116.89%、82.98%～119.22%。结论本方法操作简便、准确度高、重复性好,可用于科研及临床。

Objective To establish a special fluid scintillation counter method for measuring plasma renin activity and aldo- sterone. Methods According to the principle of competition, aldosterone （ ALD ） or angiotensin I （AI） in plasma （ or the standard solution） bound with a certain amount of specific antibodies to compete with the Radioactive Immune Reagent 125I-ALD or 125I-AI to produce an immune reaction. The specific antibodies was given priority to combine with ALD or AI in plasma （ or the standard solution） ,the rest bound with the 125I-ALD or 125I-AI. The compound combined with the specific antibodies was precipitated by Donkey Anti-Rabbit antibody. After centrifuged, a certain amount of the supernatant was taken, the unbinding 125I-ALD or 125I-AI was detected by ^-fluid scintillation counter. To establish corresponding standard curves, the contents of ALD or AI in samples, the plasma renin activity and the ALD/PRA ratio were acquired according to the standard curves. Results Variation coefficient RSD （ % ） was 6.18% - 10.79% ,the recovery rates of AI and ALD were 87.61% - 116.89% and 82.98% - 119.22% ,re- spectively. Conclusion The method had more simplicities, high accuracy and reproducibility, and can be applied in the research and clinic.