Circadian variations of immunoreactive gonadotropins and gonadotropin-releasing hormone (Gn RH) excretion in timed urinary samples

摘要

Timed urinary collections were obtained in normal and diabetic children. Urinary hormones excretion was measured in samples collected from 8 to 12 a.m., 12 to 4 p.m., 4 to 8 p.m. and 8 to 8 a.m. The results were corrected for each period using urine volume and were given in mIU or ng per 1 hour. In prepubertal and pubertal children, the values of gonadotropins and GnRH were found to be significantly higher (mean 2–3 fold increase) in urinary samples collected during the morning than in those obtained during the night. As plasma gonadotropins were previously shown to be increased during the night, the increase of these hormones excretion in urine might be delayed according to the half life and renal metabolism of these hormones.