Effect of Synthetic Luteinizing Hormone-Releasing Hormone (Lh-Rh) on the Release of Gonadotrophins in Children and Adolescents. Vi. Relations to Age, Sex and Puberty

Abstract

Plasma gonadotrophins (LH and FSH) were radio-immunoassayed before and after injection of 0.1 mg/m2 of synthetic luteinizing hormone\x=req-\ releasing hormone (LH-RH) in infants 1 to 12 months old, prepubertal children aged more than 12 months, and pubertal subjects of both sexes. The pubertal changes of gonadotrophins include a highly significant increase of LH pituitary mobilizable reserve in both sexes, while the FSH reserve shows a significant decrease in females and no significant variation in males. From the first year of life up to childhood, the basal blood levels of FSH and LH decrease significantly in girls but do not vary in boys, while the FSH reserve decreases significantly in girls and increases significantly in boys, the LH reserve showing a non-significant decrease in both sexes. In the first year of life, girls show a very significantly higher FSH secretion and reserve than boys, while boys have a significantly higher LH reserve than girls. After the end of the first year up to the onset of puberty, the FSH reserve remains significantly higher in girls than in boys. The interpretation of these facts is discussed.Radio-immunoassay of gonadotrophins (follicle-stimulating hormone (FSH) and luteinizing hormone (LH)) after the injection of luteinizing hormonereleasing hormone (LH-RH) evaluates the pituitary gonadotrophic reserve in

Responsivity of Pituitary Gonadotropes to Luteinizing Hormone-releasing Factor in Idiopathic Precocious Puberty, Precocious Thelarche, Precocious Adrenarche, and in Patients Treated with Medroxyprogesterone Acetate

“…(16). Normal girls in the first year of life tend to have greater amounts of readily releasable FSH (12). This observation may partially explain the data in the patients with precocious thelarche.…”

First Morning Voided Urinary Gonadotropin Measurements as an Alternative to the GnRH Test

“…For more than 40 years, the GnRH test has been considered the reference method for assessing the hypothalamic-pituitary-gonadal (HPG) axis function in pubertal disorders [3,4], because the previously used radioimmunoassay methods did not accurately measure the low basal S-LH and S-FSH levels in prepubertal children. The GnRH test appears to be a better tool for the evaluation of sexual precocity than for delayed puberty [5,6,7,8,9,10]. …”

GnRH AND hCG TESTS IN HEALTHY ADOLESCENTS AND ADULTS

“…There are few reports about the LH and FSH responses after GnRH stimulation in midpuberty or in advanced male adolescent puberty (Tanner stages 4 and 5) [4,10]. The adolescents and adults from this study presented a clear differentiated response of the pituitary gonadotropins, particularly the FSH response to the GnRH stimulus.…”

“…The results from this test are expressed as the percentage increments of the LH and FSH gonadotropins 30, 60, and 90 minutes after GnRH stimulation, or in absolute values, comparing the responses from the patients against the values from a normal population [12,15,16]. The LH and FSH responses to the GnRH stimulus are both related to sex, age, and individual sexual maturation [2,4,9,10]. The pubertal increased sensibility of the adenohypohysis to the synthetic decapeptide GnRH is an unequivocal sign of the hypothalamo-adenohypohysis-gonadal axis maturation [9].…”

“…The pubertal increased sensibility of the adenohypohysis to the synthetic decapeptide GnRH is an unequivocal sign of the hypothalamo-adenohypohysis-gonadal axis maturation [9]. The maximum increment of LH is obtained 30 min after the GnRH stimulation, and for the FSH the maximum increase could be obtained after some delay [4,10,12,15,16].…”