ABSTRACT
During the past decade, a number of reports, sometimes contradictory, appeared con-cerning the role of the pineal gland in aging.1-4 Melatonin is the main pineal hormonesynthesized from tryptophan, predominantly at night time.5 Melatonin is critical for the regulation of circadian and seasonal changes in various aspects of physiology and neuroendocrine function.5,6 As age advances, the nocturnal production of melatonin decreases in animals of various species, including in humans.7 The performance of a pinealectomy on rats produced a reduced life span8,9 whereas the syngeneic transplantation of a pineal gland from young donors into the thymus of old mice or in situ into pinealectomized old mice prolonged the life span of the recipients.10,11
In this chapter the results of studies on the effect of administration of melatonin to mice, rats, fruit flies, or worms are reviewed.
