[Age-related changes of serum 17 alpha-hydroxypregnenolone and 17 alpha-hydroxypregnenolone sulfate concentrations in infancy and childhood].

In order to clarify a part of the developmental processes of the human adrenal cortex or steroidgenesis in infancy and childhood, serum concentrations of 17 alpha-hydroxypregnenolone (17-OH-delta 5 P), 17 alpha-hydroxypregnenolone-3-sulfate (17-OH-delta 5 P-S) and 17 alpha-hydroxyprogesterone (17-OH-delta 4 P) were measured using a combined radioimmunoassay method previously reported, and age-related changes of these steroids were evaluated. In addition to the serum concentrations, a ratio of 17-OH-delta 5 P-S to 17-OH-delta 5 P (S/delta 5 P ratio) and that of 17-OH-delta 4 P to 17-OH-delta 5 P (delta 4 P/delta 5 P ratio) were also estimated as the indices of the activities of steroid sulfokinase (SK) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD), respectively. Serum 17-OH-delta 5 P, 17-OH-delta 5 P-S and 17-OH-delta 4 P concentrations in umbilical cord blood were 13.5 +/- 6.02 (Mean +/- SD) ng/ml, 965 +/- 363 ng/ml and 46.3 +/- 21.1 ng/ml, respectively. These values decreased consecutively to the nadirs which were 0.47 +/- 0.16 ng/ml in subjects 1 to 2 years old, 1.26 +/- 0.82 ng/ml in subjects 3 to 6 years old and 0.17 +/- 0.007 ng/ml in subjects 3 to 4 months old, respectively, and they were followed by gradual increases up to the adult levels. S/delta 5 P ratio also showed the same profile.(ABSTRACT TRUNCATED AT 250 WORDS)