Evidence for a dose-dependent effect in the sex-specific plasma prolactin response to naloxone in humans.
In attempt to ascertain if the sex specific plasma PRL response to naloxone, that we suggested in previous studies, was a dose dependent effect, 26 healthy volunteers were studied. They received naloxone 2 mg and 4.8 mg or a volume matched of saline i.v. as a bolus. Blood samples were collected and plasma PRL was measured by double antibody RIA. Naloxone, at dose of 2 mg, was able to decrease significantly plasma PRL levels in normally menstruating women (p less than 0.05 at 60 min.; p less than 0.01 at 120 min.), but not in post-menopausal ones and in men. In addition, the dose of 4.8 mg of the drug did not change plasma PRL in any group. These results suggest a dose-dependent effect in the sex specific PRL response to naloxone in humans.
D000328:Adult; D004305:Dose-Response Relationship, Drug; D004723:Endorphins / Q000502:physiology; D005260:Female; D006801:Humans; D008297:Male; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D011388:Prolactin / Q000097:blood* / Q000378:metabolism; D012636:Secretory Rate / Q000187:drug effects; D012737:Sex Factors
D004723:Endorphins; D009270:Naloxone; D011388:Prolactin