Montero J, Soto J, Fardella C, Foradori A, Valdés G
Departamento de Medicina Interna, Pontificia Universidad Católica de Chile.
Rev Med Chil. 1998 Feb;126(2):151-4.
The present method to measure plasma renin activity is cumbersome and imprecise, factors that limit its clinical application.
To assess the importance of blood sampling conditions and the usefulness of increasing incubation time to measure plasma renin activity at low levels.
Twenty hypertensive patients, 14 female, aged 14 to 76 years old, were studied. Two blood samples were obtained after a 10 min rest in the sitting position and after a 30 min rest in supine position. One blood sample of each condition was sent to the laboratory at room temperature and the other sample was sent refrigerated. Angiotensin I concentration was determined after 3 h of enzymatic incubation at 37 degrees C and, in subjects with an activity of less than 1 ng/ml/h, after 18 h of incubation.
No significant differences in plasma renin activity were observed between the samples obtained with different rest times or different transportation methods. In people with low plasma renin activity, the 18 h enzymatic incubation reduced the lower detection from 0.3 to 0.014 ng/ml/h and the coefficient of variation from 14.4 to 3.2%.
A simplified blood sampling method does not change plasma renin activity values, and the longer enzymatic incubation in people with low plasma renin activity improves both the sensitivity and accuracy of the determination.
目前测量血浆肾素活性的方法繁琐且不精确，这些因素限制了其临床应用。
评估采血条件的重要性以及延长孵育时间对测量低水平血浆肾素活性的有用性。
研究了20例高血压患者，其中14例女性，年龄14至76岁。在坐位休息10分钟后和仰卧位休息30分钟后采集两份血样。每种条件下的一份血样在室温下送至实验室，另一份冷藏送检。在37℃酶孵育3小时后测定血管紧张素I浓度，对于活性低于1 ng/ml/h的受试者，在孵育18小时后测定。
不同休息时间或不同运输方式采集的样本之间，血浆肾素活性未观察到显著差异。在血浆肾素活性较低的人群中，18小时酶孵育将最低检测限从0.3降至0.014 ng/ml/h，变异系数从14.4%降至3.2%。
简化的采血方法不会改变血浆肾素活性值，对于血浆肾素活性较低的人群，延长酶孵育时间可提高测定的灵敏度和准确性。
