García Zozaya J L, Padilla Viloria M, Callegari C, Castro A
Arch Inst Cardiol Mex. 1983 Mar-Apr;53(2):105-15.
The plasma renin activity (PRA) was determined by radioimmunoassay in 102 subjects with normal blood pressure. In this group, 56 were female and 46 male, their ages ranged between 13 and 90 years, they were not receiving any medication and their diet contained normal amounts of sodium and potassium. In addition to the PRA measurements, their weight, height, blood pressure, hemoglobin, hematocrit, serum and urinary sodium, potassium, chloride as well as proteinuria and creatinine clearance were studied. A significative correlation was found between the PRA and age. However, no correlation was found between PRA and urinary sodium. The subjects were also divided in three groups: I. less than 30 years old. II. between 30 and 60 years old, and III. over 60 years. A significative correlation between PRA and urinary sodium was found in group II. These results in group II could be explained by the finding of a daily urinary sodium excretion below 250 mEq. Age has a definite influence between PRA and urinary sodium. We found that important changes in the response of the yuxtaglomerular apparatus to the intake of sodium develop around the age of 60. In group II is where we found a more stable equilibrium in PRA. In group I, the response of the PRA to a low intake of sodium was faster and violent, where as in group III the response was slower. Finally we think it is very important in these type of studies to follow very strict methodology, because it is the only way to establish comparisons between the different ethnic groups.
采用放射免疫分析法测定了102名血压正常受试者的血浆肾素活性（PRA）。该组中，女性56名，男性46名，年龄在13至90岁之间，未接受任何药物治疗，饮食中钠和钾含量正常。除了测量PRA外，还研究了他们的体重、身高、血压、血红蛋白、血细胞比容、血清和尿钠、钾、氯以及蛋白尿和肌酐清除率。发现PRA与年龄之间存在显著相关性。然而，未发现PRA与尿钠之间存在相关性。受试者还被分为三组：I. 小于30岁。II. 30至60岁之间，以及III. 60岁以上。在II组中发现PRA与尿钠之间存在显著相关性。II组的这些结果可以通过每日尿钠排泄量低于250 mEq来解释。年龄对PRA和尿钠之间有明确影响。我们发现，肾小球旁器对钠摄入的反应在60岁左右会发生重要变化。在II组中我们发现PRA处于更稳定的平衡状态。在I组中，PRA对低钠摄入的反应更快且更剧烈，而在III组中反应较慢。最后，我们认为在这类研究中遵循非常严格的方法非常重要，因为这是在不同种族群体之间进行比较的唯一途径。
