ABSTRACT
In the course of aging, the incidence of both acute and chronic heart diseases, systematicallyincreases. Concentrations of some hormones decrease in the course of aging, e.g.,melatonin concentrations in serum and urinary levels of its main metabolite, 6-sulphatoxymelatonin, are lower in older, when compared to values observed in younger population. The evidence obtained during the last 10 years suggests that melatonin exerts certain effects upon the cardiovascular system. The presence of vascular melatoninergic receptors (binding sites) has been demonstrated; these receptors are functionally associated with either vasoconstrictor or vasodilatory effects of melatonin.
