The renin system: Variations in man measured by radioimmunoassay or bioassay.
The renin system: Variations in man measured by radioimmunoassay or bioassay.
复制标题
肾素系统：通过放射免疫测定或生物测定测量的人体变异。
作者：
J. Sealey;J. Gerten;J. Laragh
renin系统：用放射免疫测定法或生物测定法测量人体的变化。使用基本的孵育程序，然后用升压生物测定法或血管紧张素I的放射免疫测定法，血浆肾素活性（PRA）正常值在52名正常人中，在与钠平衡变化有关的生理变化范围内，确定了两种不同方法的结果。基于所观察到的血管紧张素I的较低升压活性的校正因子。血浆肾素活性与尿钠排泄的每日速率呈现一致的动态关系。当钠排泄高于150 mEq/天时，该值范围为0.5至2.8 ng/ml/hr，当钠排泄在50至150 mEq/天之间时，该值范围为1.4至6.3 ng/ml/hr，当钠排泄低于50 mEq/天时，最高可达21 ng/ml/hr。然而，一个更精确的指数来自于使用整个曲线作为诺模图的界限。血浆肾素底物测量值不随钠平衡的变化而变化。放射免疫测定法测得的血浆肾素底物浓度范围为900 - 2200 ng/ml，这些值比以前报道的测定法高得多，但更接近真实值，以前报道的测定法错误地将温育期间产生的血管紧张素I与更升压的血管紧张素II进行比较。通过向血浆中加入固定量的纯化人肾素而得到的任意指数，正常人的平均反应速度为59 × 103 ng/ml/hr/min，而与底物绝对浓度成正比。GU肾素，范围为35 - 89 ng/ml/hr/GU。这些观察结果符合一级动力学，其中酶和底物浓度都是速率限制性的。底物浓度的变化通常不是血管紧张素生成速率的决定因素，因为底物浓度与血管紧张素生成速率之间没有关系。结果表明，在43例良性原发性高血压患者中，两肾均有相当数量的血浆肾素分泌，当平均动脉血浆肾素活性为1.62 ng/ml/hr时，平均肾静脉血浆肾素活性超过动脉血浆肾素水平0.48 ng/ml/hr。
The renin system: Variations in man measured by radioimmunoassay or bioassay.Using a basic incubation procedure followed by either pressor bioassay or radioimmunoassay of angiotensin I, normal values for plasma renin activity (PRA) were defined in 52 normal subjects over the range of physiological variation which occurs in relation to changes in sodium balance.Complete interchangeability of results derived from the two different methods was achieved by the application of a correction factor based on the observed lower pressor activity of angiotensin I.Plasma renin activity exhibits a consistent dynamic relationship to the daily rate of urinary sodium excretion.The values ranged from 0.5 to 2.8 ng/ml/hr when sodium excretion was above 150 mEq/day, from 1.4 to 6.3 ng/ml/hr when sodium excretion was between 50 and 150 mEq/day, and up to 21 ng/ml/hr when sodium excretion was below 50 mEq/day.However, a more precise index derives from using limits inscribed by the whole curve as a nomogram.Plasma renin substrate measurements did not vary with changes in sodium balance.Its concentration measured by radioimmunoassay ranged from 900 to 2200 ng/ml but intra-individual variation was small.These values are considerably higher but closer to the true value than previously reported assays which erroneously compared angiotensin I generated during the incubation with the more pressor angiotensin II.Renin substrate "reactivity", an arbitrary index derived from adding a fixed amount of purified human renin to plasma, also did not vary with changes in sodium balance but it did vary directly with the absolute substrate concentration.In normal subjects the mean reaction velocity was 59 × 10 3 ng/ml/hr/GU renin and this ranged from 35 to 89 ng/ml/hr/GU.These observations are in keeping with first order kinetics in which both enzyme and substrate concentrations are rate limiting.However, the study demonstrates that physiologically, changes in substrate concentration are not normally determinants of the rate of angiotensin generation since there was no relationship between substrate concentration and the endogenous level of plasma renin activity.Systemic arterio-venous differences in plasma renin were not observed.However, in 43 patients with benign essential hypertension, net and fairly equal secretion of renin by the two kidneys was demonstrated.Mean renal vein renin activity exceeded arterial levels by 0.48 ng/ml/hr when the mean arterial renin activity was 1.62 ng/ml/hr.