The effect of atenolol, a beta1-adrenergic antagonist, on nocturnal plasma melatonin secretion: evidence for a dose-response relationship in humans

J Pineal Res. 1997 Oct;23(3):131-5. doi: 10.1111/j.1600-079x.1997.tb00345.x.


Pineal beta1-adrenergic receptors are involved in the regulation of melatonin secretion. The involvement of beta1-adrenergic receptors has been demonstrated by the ability of acute administration of beta-antagonists to suppress the nocturnal rise of circulating melatonin and its urinary metabolite 6-sulphatoxymelatonin (aMT6s). The present study was undertaken to examine the relationship between increasing doses of atenolol and nocturnal plasma melatonin concentrations. Six healthy subjects participated in the study for a period of 5 weeks. Subjects were administered placebo, 12.5, 25, 37.5, and 50 mg doses of atenolol in a randomized single blind design. Each dose was separated by a 1 week washout period. Blood samples were collected at regular intervals from 19.00 hr to 06.00 hr. Repeated measures analysis of variance showed a dose-dependent decrease in plasma melatonin concentrations (P<0.01). A Student Newman-Keuls post hoc test indicated significant differences between placebo and all doses of atenolol (P<0.05). The results demonstrate a dose-dependent relationship between beta1-receptor blockade and suppression of nocturnal plasma melatonin in humans.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adrenergic beta-Antagonists / administration & dosage*
  • Adult
  • Atenolol / administration & dosage*
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Male
  • Melatonin / blood*
  • Pineal Gland / drug effects
  • Radioimmunoassay
  • Receptors, Adrenergic, beta-1 / drug effects*
  • Single-Blind Method


  • Adrenergic beta-Antagonists
  • Receptors, Adrenergic, beta-1
  • Atenolol
  • Melatonin