Allopregnanolone levels decrease after gonadotropin-releasing hormone analog stimulation test in girls with central precocious puberty.
BACKGROUND
Allopregnanolone, a neuroactive steroid mainly secreted by adrenals and gonads, is a hormone that seems to play a role in precocious puberty, as demonstrated by its high baseline levels found in girls with central precocious puberty (CPP). Allopregnanolone concentrations significantly increase after GnRH and ACTH stimulation test suggesting both its ovarian and adrenal production.


OBJECTIVE
Aim of this study was to evaluate allopregnanolone concentrations after GnRH and GnRH agonist analog stimulation test in girls with CPP to better establish its secretion source.


METHODS
Gonadotropins and steroid hormones were evaluated in different days after GnRH and triptorelin stimulation test in 15 CPP girls.


RESULTS
After GnRH stimulation, LH, FSH, and allopregnanolone concentrations significantly increased (p<0.05). After triptorelin administration LH, FSH, estradiol and DHEAS levels significantly increased (p<0.05), while allopregnanolone concentrations significantly decreased (1.08±0.24 vs 0.87±0.28 nmol/l; p=0.003).


CONCLUSIONS
The different response of allopregnanolone to GnRH and GnRH agonist analog might reflect the agonist and antagonist action exerted by these secretagogues. Our data suggest the prevalent gonadal allopregnanolone production in CPP subjects and the usefulness of its measurement in the diagnosis of CPP.
Predieri
B
B
Department of Pediatrics, University of Modena and Reggio Emilia, Via del Pozzo 71, 41100 Modena, Italy. barbara.predieri@unimore.it
Luisi
S
S
Casarosa
E
E
Farinelli
E
E
Antoniazzi
F
F
Wasniewska
M
M
Bernasconi
S
S
Petraglia
F
F
Iughetti
L
L
D000365:Age Determination by Skeleton; D002648:Child; D002675:Child, Preschool; D015536:Down-Regulation; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D005836:Genitalia, Female / Q000000981:diagnostic imaging; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives* / Q000627:therapeutic use*; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood; D010901:Pituitary Function Tests / Q000379:methods*; D011280:Pregnanolone / Q000097:blood* / Q000378:metabolism; D011629:Puberty, Precocious / Q000097:blood / Q000175:diagnosis* / Q000378:metabolism; D017329:Triptorelin Pamoate / Q000627:therapeutic use*
D017329:Triptorelin Pamoate; D007987:Gonadotropin-Releasing Hormone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D011280:Pregnanolone