GnRH agonist stimulation of the pituitary–gonadal axis in children: age and sex differences in circulating inhibin-B and activin-A
| Autor: | Robert L. Rosenfield, Vasantha Padmanabhan, David James Phillips, Pamela R. Olton, Carol M. Foster, Daniel D Elsholz |
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| Rok vydání: | 2004 |
| Předmět: |
Male
Agonist endocrine system medicine.medical_specialty Adolescent medicine.drug_class Puberty Precocious Stimulation Gonadotropin-Releasing Hormone Follicle-stimulating hormone Reference Values Internal medicine medicine Humans Inhibins Child Gonads Growth Disorders Testosterone Inhibin-beta Subunits Sex Characteristics Bone Development biology Puberty Rehabilitation Age Factors Obstetrics and Gynecology Pituitary gonadal axis Activins Endocrinology Reproductive Medicine Pituitary Gland biology.protein Female Follicle Stimulating Hormone Leuprolide hormones hormone substitutes and hormone antagonists Follistatin Endocrine gland Sex characteristics |
| Zdroj: | Human Reproduction. 19:2748-2758 |
| ISSN: | 1460-2350 0268-1161 |
| Popis: | BACKGROUND: Inhibin-B decreases and activin increases FSH secretion in adults. We investigated whether an FSH –inhibin/activin feedback loop exists before or during puberty. METHODS: FSH secretion was stimulated with 10mg/kg leuprolide acetate (GnRH agonist) in 18 girls, ages 1.0– 13.2 years, and 11 boys, ages 8.9– 15.2 years, with variations in pubertal development, and in five normal 9- to 10-year-old girls. Blood, obtained at 0, 0.5, 1, 2, 4, 8, 12, 16, 20 and 24 h after GnRH agonist, was analysed for LH, FSH, activin-A, inhibin-A, inhibin-B, follistatin 288 and estradiol/testosterone. RESULTS: FSH increased within 30 min of GnRH agonist administration with a peak greater in girls than boys (P 5 0.0006). Baseline inhibin-B was greater in boys than girls (P 5 0.01), while baseline activin-A concentrations were greater in girls. GnRH agonist-stimulated FSH increased inhibin-B in girls by 8 h and in boys by 20 h ( P< 0.05), but did not affect activin-A. Inhibin-B increases were seen only in girls older than 5 years. CONCLUSIONS: An inhibin-B– FSH feedback loop exists prior to the onset of puberty in girls older than 5 years. Sex differences in activin-A and inhibin-B concentrations may be responsible for sex differences in serum FSH concentrations. |
| Databáze: | OpenAIRE |
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