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Comparison of urinary 6 β ‐hydroxycortisol/cortisol ratio between neonates and their mothers
Author(s) -
Nakamura Hiroyoshi,
Hasegawa Atsushi,
Kimura Maharu,
Yamagata Shinichi,
Nakasa Hiromitsu,
Osada Hisao,
Sekiya Souei,
Ohmori Shigeru,
Kitada Mitsukazu
Publication year - 1999
Publication title -
british journal of clinical pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.216
H-Index - 146
eISSN - 1365-2125
pISSN - 0306-5251
DOI - 10.1046/j.1365-2125.1999.00857.x
Subject(s) - urinary system , cyp3a , endocrinology , pregnancy , medicine , urine , gestation , hydrocortisone , biology , metabolism , cytochrome p450 , genetics
Aims To assess CYP3A enzyme activity in human neonates by measuring the urinary 6β‐hydroxycortisol/cortisol (6β‐OHF/C) ratio.Methods Fifty‐six mature male neonates with normal delivery, seventeen of their mothers and twenty‐four healthy non‐pregnant young women participated in this study. Urinary 6β‐OHF/C ratio was determined on the day of birth in neonates and their mothers. In addition, changes in the ratio after birth were determined in neonates.Results On the day of birth, the urinary 6β‐OHF/C ratio of neonates was significantly higher than that of their mothers (20.5 vs 6.9). In contrast, no significant difference was observed in the mean ratio of urinary 6β‐OHF/C between women with and without pregnancy (6.9 vs 9.0). The urinary 6β‐OHF/C ratio after birth was decreased day by day in neonates.Conclusion These results indicate that the high urinary 6β‐OHF/C ratio in mature neonates on the day of birth is independent of the activity of CYP3A enzyme in their mothers.