C16 HYDROXYLATION OF 3-BETA-HYDROXY-DELTA(5)-STEROIDS DURING THE EARLY NEONATAL-PERIOD

Temporal changes of the serum levels of 16-hydroxypregnenolone (3 beta ,16x-dihydroxy-5-pregnen-20-one) 3-sulfate (16-OH-Preg S) and 16-hydro xydehydroepiandrosterone (3 beta,16x-dihydroxy-5-androsten-17-one) 3-s ulfate (16-OH-DHEA S) were investigated by analyzing the levels of the ir precursor steroids, pregnenolone (3 beta-hydroxy-5-pregnen-20-one) 3-sulfate (Preg S) and dehydroepiandrosterone (3 beta-hydroxy-5-andros ten-17-one) 3-sulfate (DHEA S), respectively, in the early neonatal pe riod, The serum levels of these steroids mere measured by GC-MS in ful l-term (gestational age: 37-41 weeks), pre-term (gestational age: 28-3 6 weeks) and extremely immature (gestational age: 24-27 weeks) infants , The changes in 16-hydroxysteroid production were also investigated b y analyzing the ratios of the serum levels of 16-OH-Preg S anal Preg S (16-OH-Preg S/Preg S ratio), and 16-OH-DHEA S and DHEA S (16-OH-DHEA S/DHEA S ratio), It was confirmed that the 16-hydroxylation of DHEA S and Preg S increased after birth, and the 16-OH-Preg S/Preg S ratio in full-term infants was significantly higher than in pre-term and extre mely immature infants at days 0, 1-6 and 7-13, On the other hand, ther e were no significant differences between the 16-OH-DHEA S/DHEA S rati os of the three groups at days 0, 1-6 or 7-13, The mechanism of differ ences in the 16-hydroxylation of Preg S and DHEA S is also discussed.