Effect of Indomethacin on Monoamine Metabolism and Melatonin Synthesis in Rat Pineal Gland

Abstract
Indomethacin treatment of rats resulted in a significant increase of pineal monoamine oxidase (MAO) type A activity, whereas it depressed MAO type B and hydroxyindole-O-methyl transferase activities. Indomethacin also significantly impaired the nocturnal rise of pineal serotonin-N-acetyltransferase activity and melatonin content. These results suggest a role for prostaglandins in the regulation of pineal function.