RT Journal Article SR Electronic T1 Control of Pineal N-Acetylserotonin by a Beta Adrenergic Receptor JF Molecular Pharmacology JO Mol Pharmacol FD American Society for Pharmacology and Experimental Therapeutics SP 605 OP 611 VO 9 IS 5 A1 MICHAEL BROWNSTEIN A1 JUAN M. SAAVEDRA A1 JULIUS AXELROD YR 1973 UL http://molpharm.aspetjournals.org/content/9/5/605.abstract AB A specific and sensitive assay for N-acetylserotonin, the precursor of the pineal hormone melatonin, is described. The levels of N-acetylserotonin in the pineal gland rise in vivo after the administration of l-isoproterenol. l-Propranolol, a beta adrenergic blocking agent, reverses the rise in N-acetylserotonin caused by isoproterenol within 15 min. Phentolamine, an alpha adrenergic blocking agent, is without effect. Turning on the lights or administering l-propranolol at night causes a rapid decrease in the amount of N-acetylserotonin in the pineal. Thus the level of N-acetylserotonin varies as does the level of N-acetyltransferase, which in turn is controlled by stimulation of a beta adrenergic receptor. ACKNOWLEDGMENT The authors thank Dr. Takeo Deguchi for his helpful criticism and advice throughout the course of these studies.