| Abstrakt: |
Plasma renin activity was determined in 25 healthy, full-term, newborn infants aged 1 day to 9 weeks. High values were found, the mean level at 1–2 days of life (24.8 ± 8.4 ng/ml/hr, SE) being significantly higher than the mean levels at 7–9 days (5.8 ± 1.5) and at 4–9 weeks (8.1 ± 1.3) (P< 0.05). No correlation was found between plasma renin activity and systolic blood pressure, hematocrit, creatinine clearance, serum sodium, or serum potassium. Plasma renin activity (log values) was inversely correlated with sodium intake (r= −0.58) or with urinary sodium (r= −0.44), and positively with urinary osmolality (r= 0.67). The correlations reached higher coefficients if only infants aged ≤ 9 days were considered. |
