Publisher's Synopsis
Melatonin is a pineal hormone which is considered by many to act mainly, if not exclusively, on the pituitary and central nervous system. In addition to this classical theory of the central actions of pineal melatonin, this publication presents results consistent with the hypothesis of direct melatonin actions on peripheral tissues. Detailed information on the peripheral effects; the presence of putative melatonin receptors labeled by the specific melatonin agonist 2-[125I]iodomelatonin; the possible transduction mechanism of melatonin-receptor complex; and the physiological or pharmacological regulation of putative melatonin receptors on the gut, kidney, vas deferens, blood vessels, heart and lung are reviewed and discussed.;The above findings disclosed a new area of pineal melatonin research. Future investigations on the evolutionary implication, mechanisms of action, physiological functions and pharmacological effects are suggested. The evidence discussed also opens the door for investigations of different subtypes of melatonin receptors in different tissues and the development of new ligands and drugs related to melatonin actions including the regulation of diurnal and seasonal biorhythms.
