Secretory function of the endothelium as a factor of vascular tone regulation in the norm and in cardiovascular pathology

Endothelin-1 and nitric oxide are the most potent factors of the endothelium-derived substances. The factors play opposite roles in regulation of cardiovascular system, and their interaction underlies the balance of vasoconstrictor and vasodilator influences on vascular tone under normal conditions. In our experiments, changes in endothelin-1 blood concentration were associated with affected production of endogenous nitric oxide. The altered interrelationships between the endothelium-derived vasoactive substances may precede pathological shifts in the cardiovascular system.