PLASMA ALDOSTERONE LEVELS AT BIRTH IN RELATION TO LATER AGE

Plasma aldosterone (PA) concentration was measured in 27 women undergoing uncomplicated vaginal delivery and simultaneously in cord blood specimens. Furthermore, 67 children in the age groups 0–1, 1–6, 6–10, and 10–14 yrs were studied using a sensitive radioimmunoassay method developed in our laboratory. Purification of the plasma extract is achieved by thin layer chromatography. PA-levels in supine position for at least one hour and sampled from children at 8 a.m. were as follows: a) women, vag.del. 68,6±39,3 ng/100 ml; b) cord blood 75,5±37,4; c) 0–1 age (N=15) 25,7±16,2; d) 1–6 age(N=16) 5,7±3,6; e) 6–10 age (N=15) 8,5±5,0; f) 10–14 age (N=21) 7,8±5,0. There is no significant difference between the age groups d-f (p>0,1), but the mean plasma level of aldosterone in infants less than one year of age was found to be significantly higher (p<0,025) in agreement with KOWARSKI et.al. Women at delivery showed markedly elevated concentrations without differences compared with cord blood specimens. Possible explanations for this phenomenon are discussed.