The effect of atenolol, a β1-adrenergic antagonist, on nocturnal plasma melatonin secretion: Evidence for a dose-response relationship in humans

Abstract

Pineal β1-adrenergic receptors are involved in the regulation of melatonin secretion. The involvement of β1-adrenergic receptors has been demonstrated by the ability of acute administration of β-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 p..