In Pubertal Girls, Naloxone Fails to Reverse the Suppression of Luteinizing Hormone Secretion by Estradiol1

Autor: Vasantha Padmanabhan, Carol M. Foster, Wensheng Guo, Ayse Pinar Cemeroglu, Robert P. Kelch, John C. Marshall, Gad B. Kletter, Morton B. Brown
Rok vydání: 1998
Předmět:
Zdroj: The Journal of Clinical Endocrinology & Metabolism. 83:3501-3506
ISSN: 1945-7197
0021-972X
Popis: Estradiol (E2) negative feedback on LH secretion was examined in 10 pubertal girls, testing the hypothesis that E2 suppresses LH pulse frequency and amplitude through opioid pathways. At 1000 h, a 32-h saline infusion was given, followed 1 week later by an E2 infusion at 13.8 nmol/m2·h. During both infusions, four iv boluses of saline were given hourly beginning at 1200 h, and four naloxone iv boluses (0.1 mg/kg each) were given hourly beginning at 1200 h on the following day. Blood was obtained every 15 min for LH determination and every 60 min for E2 determination from 1200 h to the end of the infusion. E2 infusion increased the mean serum E2 concentration from 44 ± 17 to 112 ± 26 pmol/L (P < 0.01). The mean LH concentration between 2200–1200 h decreased from 3.19 ± 0.89 to 1.99 ± 0.65 IU/L (P = 0.014), and LH pulse amplitude decreased from 3.4 ± 0.6 to 2.6 ± 0.5 IU/L (P = 0.0076). Although there were 1.2 fewer pulses during E2 infusion compared to saline infusion, differences did not reach significance...
Databáze: OpenAIRE