Serum luteinizing radioi m m u noassa y hormone by in normal children

Using a sensitive radioimmunoassay, luteinizing hormone (LH) levels have been determined in 249 normal children (5 to 18 years of age), 30 normal adult males, 2 normal adult females throughout a menstrual cycle, and 19 patients with pituitary deficiency. The mean levels in prepubertal boys and girls were comparable (3.4 and 2.8 m.l.U, per milliliter, respectively) and began increasing at the same age (10 to 12 years) in both sexes. An increase in serum LH was noted in the males but not in the females before beginning sexual maturation was apparent clinically. In adult males and females, the mean serum LH levels (10.9 and 10.2 m.I.U, per milliliter, respectively) were approximately 3.5 times prepubertal values. Patients with pituitary deficiency had a very low mean level (1.7 m.I.U, per mililiter), but some immunochemical LH was found in all sera. In males, the urinary excretion of 17-ketosteroids had a statistically significant correlation (correlation coefficient ~ 0.73) with the serum LH determinations.