Melatonin and aging. A brief survey.

The relationship between the pineal gland and aging has been assumed already nearly a century ago. Recently, melatonin was considered by some authors as a "wonder drug." The present paper tries to summarize the relationship between melatonin and aging in three points. 1. Decline of melatonin production during aging. 2. The role of the pineal gland in the regulation of the ovarian cycle in aged females. 3. The antioxydant effect of melatonin and aging. The age-related decline of pineal melatonin production is due to the degenerative changes of the neural structures (serotonergic and noradrenergic neuron systems) innervating the pineal gland and the suprachiasmatic nuclei rather than to the degeneration of the pineal tissue itself. The decreased melatonin production of the pineal gland preceds the destruction of ovarian cyclicity which can be partly counteracted by melatonin or by 5-hydroxytryptophane administration. The antioxydant effect of melatonin might explain its lifespan-prolonging effect, at least to a certain degree.