Circulating levels of angiotensin I measured by radioimmunoassay in hypertensive subjects.
Circulating levels of angiotensin I measured by radioimmunoassay in hypertensive subjects.
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通过放射免疫测定法测量高血压受试者血管紧张素 I 的循环水平。
DOI：
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发表时间：
1979
期刊：
影响因子：
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通讯作者：
G. Liddle
中科院分区：
文献类型：
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作者：
R. Workman;C. Sussman;D. Burkitt;G. Liddle
开发了一种独特的灵敏度和特异性的抗血清AI导致建立了放射免疫测定能够检测7.5 pg的AI每毫升血浆。由于其灵敏度，该测定允许测量AI的循环水平，避免了先前描述的AI测定的许多有争议的方面，这些方面都需要在37 ° C下的孵育步骤以允许肾素催化形成足够的AI或提取程序以浓缩足够的肽以使定量可行。由于该测定的灵敏度也取决于非常纯的痕量的可用性，因此描述了制备比活度大于1000微居里/微克的单碘化125 I-AI的方法。为了证明该测定的通用性和灵敏度，测量了响应于生理刺激的循环AI水平的变化。从88名受试者的肾静脉下方的下腔静脉中采集仰卧位和直立位的血液样本。血浆数值范围为12 - 1990 pg/ml。在直立倾斜期间，88名患者中有85名显示AI水平升高，该组的平均值从220 pg/ml增加到385 pg/ml。3例受试者同时从下腔静脉和外周动脉和/或静脉中采集样本。所有三个采样点的AI量基本相同。17例原发性高血压患者接受了1.5 L生理盐水的输注，并在输注开始前和输注开始后120 min和150 min测定循环AI水平。所有17名受试者的AI水平均受到抑制，0、120和150 min时组的平均值分别为177、55和50 pg/ml血浆。在226例来自不同病因的高血压患者的肾静脉和下腔静脉样本中，循环AI与血浆肾素活性相关良好（r = 0.87009）。
The development of a uniquely sensitive and specific antiserum to AI has led to the establishment of a radioimmunoassay capable of detecting 7.5 pg of AI per milliliter of plasma. Due to its sensitivity this assay permits the measurement of circulating levels of AI, obviating many of the controversial aspects of previously described AI assays which all required either an incubation step at 37 degrees C to allow renin to catalyze the formation of sufficient AI or an extraction procedure to concentrate sufficient peptide to make quantification feasible. Since the sensitivity of this assay also depends upon the availability of very pure trace, a method is described for preparing monoiodinated 125I-AI of specific activity greater than 1000 microCi/microgram. To demonstrate the versatility and sensitivity of this assay, changes in circulating AI levels in response to physiologic stimuli were measured. Blood samples were obtained from 88 subjects from the inferior vena cava below the renal veins in both the supine and upright positions. Values ranged from 12 to 1990 pg/ml of plasma. Eighty-five of the 88 displayed a rise in the AI level during an upright tilt, the mean for the group increasing from 220 to 385 pg/ml of plasma. Three subjects had samples drawn simultaneously from the inferior vena cava and a peripheral artery and/or vein. The amounts of AI in all three sampling locations were essentially the same. Seventeen patients with essential hypertension underwent an infusion of 1.5 L of normal saline, and circulating AI levels were determined before and 120 and 150 min after the start of the infusion. All 17 experienced suppression of their AI levels, the mean for the group at 0, 120 and 150 min being 177, 55, and 50 pg/ml of plasma, respectively. Circulating AI correlated well (r = 0.87009) with plasma renin activity in 226 samples from the renal veins and inferior vena cava from individuals with hypertension of various etiologies.