TY - JOUR
T1 - Acute effects of testosterone infusion on the serum luteinizing hormone profile in eumenorrheic and polycystic ovary syndrome adolescents
AU - Ropelato, María Gabriela
AU - Rudaz, María Cecilia García
AU - Escobar, María Eugenia
AU - Bengolea, Sonia Viviana
AU - Calcagno, María Luján
AU - Veldhuis, Johannes D.
AU - Barontini, Marta
N1 - Funding Information:
This work was supported by grant of the Consejo de Investigación en Salud of the Gobierno de la Ciudad de Buenos Aires to M.G.R. M.G.R. and M.E.E. are research members of the Gobierno de la Ciudad Autónoma de Buenos Aires. M.B. is a research member of the Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET).
PY - 2009/9
Y1 - 2009/9
N2 - Context: Little is known about the neuroendocrine effects of androgens on the GnRH-LH unit in females. Objective: Our objective was to evaluate androgen negative feedback on the GnRH-LH axis in eumenorrheic and polycystic ovary syndrome (PCOS) adolescents. Design and Setting:Weconducted a prospective, longitudinal, randomized, double-blind study at a pediatric endocrinology clinical research center. Participants: Seven nonobese PCOS adolescents and seven matched controls (C) were studied in the early follicular phase of three consecutive menstrual cycles or in three consecutive months. Intervention: Pulsatile LH release was determined during saline [baseline (B)] and constant testosterone (T) infusions: low dose (T-LD) 0.75 and high dose (T-HD) 2.5 mg/12 h iv. Blood samples were drawn every 20 min overnight. Main Outcome Measures: LH (immunofluorometric assay) and T (electrochemiluminescence immunoassay) were determined at B, and during both T-LD and T-HD. LH profiles were analyzed by deconvolution and approximate entropy analyses. Results: On T-LD, C and PCOS serum T levels increased 2- to 3-fold vs. B. On T-HD, T values doubled in both groups vs. T-LD. Controls on T-LD had greater 12-h pulsatile LH secretion rate (P < 0.05 vs. B) and on T-HD had lower mean, pulsatile, basal LH release and LH approximate entropy (vs. B, P< 0.05). PCOS did not respond to T-LD. High-dose T did not alter mean LH in PCOS but increased pulsatile and reduced basal LH secretion. Conclusions: PCOS adolescents have impaired suppression of pulsatile LH secretion rate consistent with reduced androgen negative feedback. Attenuation of T feedback in nonobese adolescents with PCOS extends the pathophysiology of this syndrome.
AB - Context: Little is known about the neuroendocrine effects of androgens on the GnRH-LH unit in females. Objective: Our objective was to evaluate androgen negative feedback on the GnRH-LH axis in eumenorrheic and polycystic ovary syndrome (PCOS) adolescents. Design and Setting:Weconducted a prospective, longitudinal, randomized, double-blind study at a pediatric endocrinology clinical research center. Participants: Seven nonobese PCOS adolescents and seven matched controls (C) were studied in the early follicular phase of three consecutive menstrual cycles or in three consecutive months. Intervention: Pulsatile LH release was determined during saline [baseline (B)] and constant testosterone (T) infusions: low dose (T-LD) 0.75 and high dose (T-HD) 2.5 mg/12 h iv. Blood samples were drawn every 20 min overnight. Main Outcome Measures: LH (immunofluorometric assay) and T (electrochemiluminescence immunoassay) were determined at B, and during both T-LD and T-HD. LH profiles were analyzed by deconvolution and approximate entropy analyses. Results: On T-LD, C and PCOS serum T levels increased 2- to 3-fold vs. B. On T-HD, T values doubled in both groups vs. T-LD. Controls on T-LD had greater 12-h pulsatile LH secretion rate (P < 0.05 vs. B) and on T-HD had lower mean, pulsatile, basal LH release and LH approximate entropy (vs. B, P< 0.05). PCOS did not respond to T-LD. High-dose T did not alter mean LH in PCOS but increased pulsatile and reduced basal LH secretion. Conclusions: PCOS adolescents have impaired suppression of pulsatile LH secretion rate consistent with reduced androgen negative feedback. Attenuation of T feedback in nonobese adolescents with PCOS extends the pathophysiology of this syndrome.
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U2 - 10.1210/jc.2009-0402
DO - 10.1210/jc.2009-0402
M3 - Article
C2 - 19567528
AN - SCOPUS:69949103166
SN - 0021-972X
VL - 94
SP - 3602
EP - 3610
JO - Journal of Clinical Endocrinology and Metabolism
JF - Journal of Clinical Endocrinology and Metabolism
IS - 9
ER -