Abstracts Health Sciences

Urinary excretion of cortisol and corticosterone metabolites by the newborn infant

by Siu-Kay Chan

Cortisol, cortisone, their respective ester sulfates, tetrahydrocortisol, tetrahydrocortisone and their respective glucuronides were quantified by double isotope assays in 24-hour urine specimens obtained on the 2nd and 6th days of life from both male and female infants. On the 2nd day of life the sum of the mean urinary excretion of cortisol sulfate (60 µg/day) and cortisone sulfate (29 µg/day) represented 64% of that of tetrahydrocortisone glucuronide (138 µg/day). All other metabolites of cortisol with the exception of cortisone were excreted at a rate lower than 8 µg/day. Of 5 metabolites of corticosterone (corticosterone, 11-dehydrocorticosterone, their respective ester sulfates and tetrahydrocorticosterone glucuronide) the excretion of corticosterone sulfate (mean: 60 µg/day) was the greatest.