title: Prolonged elevation of hypothalamic opioid peptide activity in women taking oral contraceptives.
abstract: To examine the hypothesis that endogenous opioid peptide activity is chronically elevated by oral contraceptives, we infused either naloxone or saline into 10 women during the use of, or 5-6 and 9-10 days after stopping, combination birth control pills. A paradoxical increase in prolactin occurred with naloxone infusion during and 5-6 days after stopping the pills. Serum LH levels were not significantly elevated by naloxone until 9-10 days after cessation of pill use. These results suggest that hypothalamic opioid peptide activity is continuously elevated in women taking oral contraceptives.
mesh_terms: D000328:Adult; D003276:Contraceptives, Oral / Q000494:pharmacology*; D004723:Endorphins / Q000378:metabolism*; D005260:Female; D006801:Humans; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000097:blood; D009270:Naloxone / Q000494:pharmacology; D011388:Prolactin / Q000097:blood
chemical_list: D003276:Contraceptives, Oral; D004723:Endorphins; D009270:Naloxone; D011388:Prolactin; D007986:Luteinizing Hormone