Growth hormone secretion after baclofen administration in different phases of the menstrual cycle in healthy women.
OBJECTIVE
The aim of this study was to investigate the effect of baclofen administration on growth hormone (GH) secretion during different phases of the menstrual cycle.


METHODS
Twelve healthy women (33.6 +/- (SD) 2.8 years; range 23-40 years) with regular menstrual cycles were enrolled. The phases of the menstrual cycle were determined using transvaginal ultrasonography (TV-US) and detecting hormonal serum levels. Plasma GH levels were evaluated during the early follicular, periovulatory and luteal phases of the cycle before and after the baclofen challenge test.


RESULTS
After acute baclofen administration, GH levels increased significantly (p < 0.001) compared to basal values during the periovulatory and luteal phases, while no significant variation was detected during the early follicular phase. In addition, plasma GH levels resulted significantly (p < 0.001) higher during the luteal phase than during the periovulatory phase.


CONCLUSIONS
Acute baclofen administration induces a significant increase in plasma GH levels in healthy females during the periovulatory and luteal phases, but not during the early follicular phase. These data suggest a modulator role of plasma sex steroids levels on GH release induced by baclofen.
Orio
F
F
Department of Molecular and Clinical Endocrinology and Oncology, University of Naples Federico II, Naples, Italy. f.orio@tin.it
Palomba
S
S
Colao
A
A
Tenuta
M
M
Dentico
C
C
Petretta
M
M
Lombardi
G
G
Nappi
C
C
Orio
F
F
D000284:Administration, Oral; D000328:Adult; D001418:Baclofen / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D005498:Follicular Phase / Q000187:drug effects; D018755:GABA Agonists / Q000008:administration & dosage / Q000494:pharmacology; D013006:Growth Hormone / Q000097:blood / Q000378:metabolism*; D006801:Humans; D008183:Luteal Phase / Q000187:drug effects; D008597:Menstrual Cycle / Q000097:blood / Q000187:drug effects*; D010060:Ovulation / Q000187:drug effects
D018755:GABA Agonists; D013006:Growth Hormone; D001418:Baclofen