TY - JOUR T1 - Control of Pineal <em>N</em>-Acetylserotonin by a <em>Beta</em> Adrenergic Receptor JF - Molecular Pharmacology JO - Mol Pharmacol SP - 605 LP - 611 VL - 9 IS - 5 AU - MICHAEL BROWNSTEIN AU - JUAN M. SAAVEDRA AU - JULIUS AXELROD Y1 - 1973/09/01 UR - http://molpharm.aspetjournals.org/content/9/5/605.abstract N2 - 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. ER -