The effect of naloxone and metoclopramide on the secretion of luteinizing hormone in a hyperprolactinemic hypogonadotropic postmenopausal woman.
OBJECTIVE
To determine the role of opioidergic and dopaminergic activity in the suppression of GnRH0LH in a hyperprolactinemic state.


METHODS
Case report.


METHODS
University hospital.


METHODS
A 68-year-old woman with a macroprolactinoma.


METHODS
Serial 10-hour IV infusions of naloxone and metoclopramide.


METHODS
Serum LH concentration.


RESULTS
Naloxone induced a small but significant rise of serum LH levels, which displayed a pulsatile pattern. By contrast, metoclopramide elicited no significant response in LH secretion.


CONCLUSIONS
Opioidergic but not dopaminergic neurotransmission plays a direct role in the suppression of LH secondary to hyperprolactinemia.
Verhelst
J
J
Department of Endocrinology, Middelheim Hospital Antwerp, Belgium.
Beckers
A
A
Abs
R
R
D000368:Aged; D001971:Bromocriptine / Q000494:pharmacology; D018491:Dopamine Agonists / Q000494:pharmacology; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D006966:Hyperprolactinemia / Q000097:blood*; D007006:Hypogonadism / Q000097:blood*; D007275:Injections, Intravenous; D007986:Luteinizing Hormone / Q000097:blood*; D008787:Metoclopramide / Q000008:administration & dosage / Q000494:pharmacology*; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D010911:Pituitary Neoplasms / Q000097:blood; D017698:Postmenopause / Q000097:blood*; D011388:Prolactin / Q000097:blood; D015175:Prolactinoma / Q000097:blood
D018491:Dopamine Agonists; D018492:Dopamine Antagonists; D009292:Narcotic Antagonists; D009270:Naloxone; D001971:Bromocriptine; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D008787:Metoclopramide