Effects of gonadotropin-releasing hormone agonist and clomiphene citrate on estrogen/progesterone-induced hyperprolactinemia in monkeys.
The effects of follicular phase clomiphene citrate (CC) and two regimens of leuprolide acetate on estrogen-progesterone-induced hyperprolactinemia in nonhuman primates were studied. All groups received estradiol (E2) benzoate (12.5 micrograms intramuscularly on cycle days 2 to 33) and progesterone (P) (silastic implant for cycle days 14 to 33). A gonadotropin-releasing hormone agonist (GnRH-a) (Lupron 0.5 mg daily, TAP Pharmaceuticals, Chicago, IL) was administered from cycle day 2 to 14 in group II and from day 20 of the previous cycle until cycle day 14 in group III. Oral CC was given on cycle days 3 through 7 in group IV. No significant differences of mean E2 and P concentrations were noted between groups. Neither GnRH-a nor CC had an overall effect on E2/P-induced hyperprolactinemia. However, for the 5-day interval at the onset of the P treatment there was a significant increase in prolactin (PRL) secretion for group II (130.4 +/- 30.6) versus group I (53.9 +/- 3.3), group III (64.4 +/- 11.1), and group IV (68.8 +/- 14.3). This suggests that leuprolide may exert a delayed stimulatory effect on PRL secretion, or that complete suppression of the putative paracrine regulation of PRL stimulation may require more than 13 days of GnRH-a administration.
Groff
T R
TR
Department of Obstetrics and Gynecology, University of Texas Health Science Center, San Antonio 78284-7836.
Olive
D L
DL
Riehl
R M
RM
Schenken
R S
RS
D000818:Animals; D002996:Clomiphene / Q000494:pharmacology*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000097:blood / Q000494:pharmacology; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000494:pharmacology; D006728:Hormones / Q000494:pharmacology; D006966:Hyperprolactinemia / Q000139:chemically induced / Q000503:physiopathology*; D016729:Leuprolide; D008252:Macaca fascicularis; D008597:Menstrual Cycle / Q000187:drug effects; D011374:Progesterone / Q000097:blood / Q000494:pharmacology*; D011388:Prolactin / Q000097:blood / Q000378:metabolism; D011863:Radioimmunoassay / Q000379:methods; D012016:Reference Values
D006728:Hormones; D002996:Clomiphene; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin; C010452:estradiol-17 beta-benzoate; D016729:Leuprolide