Summaryother mineralocorticoids like DOC, and glucocorticoids like B and E exhibit similar patterns in different p&iatric age groups or not. Plasma aldosterone (A), corticosterone (B), deoxycorticoster-~~~~~~l~ published data on the progestins P and 1 7 -0~p with One progesterone ( ' 1,, one exception (23) during the large quantities of blood previously required for their deterthe first weeks of life, then increased significantly reaching adult mination and the sampling difficulties encountered in young levels between v of 'gee Mean progressive'y from 74 children. It prompted us to study these important parameters of after birth to l0 during Yr (' << O.OOO1), then adrenocortical function in a large number of children 'lightly increased to levels-After age yr, ' and 17-OHP, throughout all pediatric age groups using our recently developed in contrast to the other steroids, rose significantly in both boys method for the simultaneous determination of eight plasma steand girls relative to pubertal development.roids by radioimmunoassay (46) requiring only 1-3 ml of periphThe observed changes are thought to be due to (1) adaptation eral blood. of the adrenal neocortex to extrauterine life after disruption of the fetoplacental unit, (2) a physiologic lack of corticosteroid binding globulin (CBC) during infancy due to maturation of hepatic MATERIALS AND METHODS CBG biosynthesis, (3) the functional immaturity of the infant kidney compensated by an increased activity of the renin-angio-A total of 174 infants and (83 boys and 91 girls), aged tensin-aldosterone system, and (4) gradually increasing gonadal * hr-15 yr* were studied' The newborn infants were products secretion of progestins during puberty. of uncomplicated, full term pregnancies and were born by vaginal delivery after labor of spontaneous onset. Infants and children over 2 wk of age were either admitted for minor disorders or for Speculation observation, or were seen at the Outpatient Department and From birth to adulthood, marked evolutional changes were required VenepUnCtUre for diagnostic reasons. In addition, inobserved in the basal plasma concentrations of all physiologically formed consent was obtained from the mothers, fathers, or guardimportant unconjugated corticosteroids and progestins in normal ians. In the two oldest age groups (7-15 yr), there were 26 boys children. Detailed knowledge of the agedependent normal plasma and 26 girls whose pubertal development (53) ranged from Stage steroid pattern reflecting maturational processes of both the hy-1 -4 9 and from Stage 1-59 respectively. Only 5 of these girls were pothalamo-adrenocortical and the hypothalamo-gonadal axis, of after menarche. ,411 subjects included in the present study were the renin-angiotensin-aldosterone system, and of hepatic and renal without evidence of endocrine, renal, circulatory, or any other function, therefore, is a prerequisite for understanding pathologic systemic disease and did not show disturbances of acid base or conditions in pediatric endocrinology.electrolyte metab...