title: Inhibition of melatonin secretion by ethanol in man.
abstract: To determine whether ethanol inhibits nocturnal melatonin (MT) secretion, three experiments (A, B, and C) were performed in seven normal subjects. In A, ethanol at a dose of 0.34 g/kg was administered orally at 6:00, 8:00, and 10:00 PM. Each dose was increased to 0.52 g/kg in B. In C, water was substituted for ethanol. Blood samples for determination of serum MT levels were drawn every second hour between 6:00 PM and 8:00 AM. Urinary excretion of MT during the night was also determined. In A, serum ethanol reached a maximal level of 13 +/- 1 mmol/L at 12 midnight. In B, the corresponding maximum was 25 +/- 1 mmol/L. The higher alcohol dose inhibited nocturnal MT secretion by 20% +/- 5% (P < .01), whereas the lower dose lacked such effect. Urinary excretion of MT was left unaffected by alcohol at both doses. Five additional normal subjects were given alcohol as described above at a dose of 0.52 g/kg (experiment D). This induced mild nocturnal hypoglycemia as evidenced by a glucose decremental area (5.9 +/- 1.8 mmol/L.h) that differed significantly from zero (P < .05). To determine whether a reduced glucose delivery to pinealocytes might contribute to the decreased MT secretion in alcohol-intoxicated subjects, two experiments (E and F) were performed in eight healthy individuals. In E, ethanol was given orally as in B; three small oral doses of glucose were also given at 8:00 PM, 10:00 PM, and 12 midnight. In F, water was substituted for ethanol and glucose.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Internal Medicine, Södersjukhuset, Stockholm, Sweden.
authors.forename: S
authors.initials: S
authors.lastname: Röjdmark
authors.forename: J
authors.initials: J
authors.lastname: Wikner
authors.forename: N
authors.initials: N
authors.lastname: Adner
authors.forename: D E
authors.initials: DE
authors.lastname: Andersson
authors.forename: L
authors.initials: L
authors.lastname: Wetterberg
mesh_terms: D000284:Administration, Oral; D000328:Adult; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D000431:Ethanol / Q000097:blood / Q000494:pharmacology*; D005260:Female; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D006801:Humans; D007003:Hypoglycemia / Q000097:blood / Q000378:metabolism; D008297:Male; D008550:Melatonin / Q000097:blood* / Q000652:urine; D011863:Radioimmunoassay
chemical_list: D000431:Ethanol; D005947:Glucose; D008550:Melatonin