Periovulatory plasma prolactin response to synthetic growth hormone-releasing hormone in normal women.
Following the demonstration of a positive prolactin (PRL) response to growth hormone-releasing hormone (GHRH) in acromegalic and anorexic women, we have injected GHRH (50 micrograms intravenously as a bolus) in normal women during various phases of their menstrual cycle in order to establish whether a positive response was present also in normal subjects. Synthetic GHRH 1-44 elicited a significant increase in circulating PRL levels in eight women studied during the periovulatory phase of the menstrual cycle. In contrast, no significant changes in circulating PRL levels after GHRH administration were found in nine women during the midfollicular phase or in five women during the midluteal phase. A temporal correlation between the midcycle gonadotropin peak and the positive response to GHRH has been observed. Synthetic GHRH elicited the expected increase in GH levels during all phases of the cycle studied. Our data demonstrate that GHRH is capable of stimulating a PRL response in normal subjects and raise the possibility that PRL secretion is regulated by several hormones of hypothalamic origin.
De Marinis
L
L
Institute of Endocrinology, Catholic University School of Medicine, Rome, Italy.
Mancini
A
A
D'Amico
C
C
Sambo
P
P
Tofani
A
A
Calabrò
F
F
La Brocca
A
A
Barbarino
A
A
D000328:Adult; D005260:Female; D005498:Follicular Phase / Q000187:drug effects; D013006:Growth Hormone / Q000097:blood; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D006801:Humans; D008183:Luteal Phase / Q000187:drug effects; D008597:Menstrual Cycle / Q000187:drug effects*; D010060:Ovulation / Q000187:drug effects; D011388:Prolactin / Q000097:blood*
D011388:Prolactin; D013006:Growth Hormone; D013007:Growth Hormone-Releasing Hormone