Plasma gonadotropin (LH and FSH) concentrations in repubertal and pubertal children upon stimulation by LH-releasing hormone

Abstract

The simultaneous determination of LH and FSH were carried out in a single plasma sample by double antibody radioimmunoassays in a total of 26 prepubertal and pubertal children. The blood samples were taken before and after i.v. application of 25 mug synthetic LH-RH. Plasma LH and FSH concentrations found in prepubertal boys and girls at beginning of the test and at the time of maximum response were compared with those measured in pubertal boys and girls. The mean basal levels of LH and FSH are in group I (8 prepubertal girls): LH 0.6+/-0.7 (SD) mIU/ml, FSH 1.5+/-0.8 mIU/ml; in group II (6 prepubertal boys): LH 1.8+/-1.0 mIU/ml, FSH 2.0+/-0.8 mIU/ml; in group III (6 pubertal girls): LH 4.1+/-2.0 mIU/ml, FSH 4.7+/-2.8 mIU/ml; in group IV (6 pubertal boys): LH 3.5+/-2.3 mIU/ml, FSH2.0+/-1.2 mIU/ml. The mean maximum response of LH and FSH after stimulation are in group I: LH 4.1+/-2.3 mIU/ml, FSH 11.7+/-3.7 mIU/ml; in group II: LH 4.2+/-1.0 mIU/ml, FSH 6.0+/-1.1 mIU/ml; in group III: LH 19.7+/-10.6 mIU/ml, FSH 12.8+/-5.7 mIU/ml; in group IV: LH 13.4+/-5.7 mIU/ml, FSH 3.8+/-0.9 mIU/ml. It is suggested that without stimulation of the pituitary with LH-RH, plasma LH and FSH levels are not reliable parameters to test the pituitary gonadotropin reserve.