Measurement of Urinary Gonadotropins Using Immuno-fluorometric Assay

Urinary luteinizing hormone (LH) and follicle stimulating hormone (FSH) concentrations were determined by immuno-fluorometric assay (IFMA) and compared with the values determined by immuno-radiometric assay (IRMA). The results of gel chromatography of urine suggested that in IFMA immunoreactive LH consisted of both intact LH and LH β-subunit, while the immunoreactive LH in IRMA was mainly intact LH. In LH measurement, IFMA was much more sensitive than IRMA. Good correlations were observed between urinary gonadotropin concentrations corrected by urinary creatinine in first morning voided urine and mean serum gonadotropin concentrations during the first three hours of sleep.The reference ranges of urinary gonadotropins in school children aged 6-17 were determined, and the change of urinary gonadotropin concentrations according to pubertal development was investigated in normal short children. Urinary LH levels and urinary LH/FSH ratios in IFMA increased 20-fold according to age and were useful in estimating pubertal development.Urinary LH and FSH measurement by IFMA is simple and noninvasive, and therefore will be suitable for investigating gonadotropin secretion in normal and abnormal pubertal development.