Decreased melatonin biosynthesis, calcium flux, pineal gland calcification and aging: a hypothetical framework.

Increased pineal calcifications and decreased pineal melatonin biosynthesis, both age related, support the notion of a pineal bio-organic timing mechanism. Decreased calcium ion availability is the single common denominator of diminished beta-postreceptor- and alpha-receptor-stimulating functions in beta-receptor potentiation, which is necessary for nocturnal peak melatonin production. A comprehensive framework for the interaction of aging pineal cell mechanisms, calcium flux and melatonin biosynthesis is presented.