News in Physiological Sciences, Vol 1, 202-205, Copyright © 1986 by International Union of Physiological Sciences
The Pineal Gland: An Important Link to the Environment
RJ Reiter
The pineal gland has two characteristic features: 1) virtually every aspect
of its function is rhythmic and 2) its influence is extremely widespread.
The production of its hormone, melatonin, is cyclic and is synchronized by
the light-dark cycle of the environment. The reproductive consequences of
the mammalian pineal are important but may be secondary to its broader
functions as a synchronizer that entrains physiology to the appropriate
season of the year. The significance of the pronounced 24-h cycle in human
melatonin production has remained elusive.
