Human Luteinizing Hormone (LH) Activity in Processed and Unprocessed Urine Measured by Radioimmunoassay and Bioassay

Luteinizing hormone (LH) potency estimates were made on unconcentrated aliquots from 10 urine pools by radioimmunoassay and on concentrated extracts from 8 of the same urine pools by both radioimmunoassay and bioassay. Urine specimens from groups of male adults and prepubertal children and several patients with disorders of sexual development were compared. The data from radioimmunoassay of unprocessed urine showed a very narrow range of differences in LH potency estimates between the different groups, whereas both radioimmunoassay and bioassay of processed urine revealed a much greater range of differences between the different groups of subjects. There was substantial agreement between LH potency estimates on extracted urine obtained by bioassay and radioimmunoassay. It is concluded that radioimmunoassay with its attendant advantages can be substituted for bioassay in the measurement of LH on urine extracts from patients excreting relatively small amounts of gonadotropin, thus facilitating studies of variation in LH excretion in physiologic and pathologic states.