LH and FSH levels in urine and serum of prepubertal and pubertal children receiving a 3 hour infusion of LH-RH.

LH-RH was administered to 17 normal prepubertal and 14 pubertal children as well as to 6 GH deficient prepubertal patients. Urinary immunoreactive LH and FSH were measured in acetone extracts of 3 h collections prior to, during, and immediately after a 3 h infusion of 100 mug LH-RH. Peak LH excretion in response to LH-RH was higher in pubertal than prepubertal children. Girls excreted larger quantities of FSH after LH-RH than did boys. Serum LH and FSH increments evoked by LH-RH correlated significantly (P less than 0.01) with peak urinary gonadotropin excretion. These data suggest that measurement of urinary immunoreactive LH and FSH prior to and after LH-RH administration is clinically useful in evaluation of the reproductive endocrine system of young children and of individuals with low basal levels of gonadotropin.