The
present paper reviews the findings accumulated on the role
of pineal gland and its hormone melatonin in
regulation of the hypothalamo-neurohypophysial system activity.
Effects of modified photoperiod, pinealectomy or treatment
with melatonin on the vasopressin and oxytocin biosynthesis
and/or secretion have been described. Taken together, the
in vivo and in vitro data suggest that the effect of
melatonin on the vasopressin and oxytocin secretion depends
on this pineal hormone concentration and experimental conditions.