[The pharmacology of endothelium-dependent vascular reactions].

The review deals with the critical analysis of the recent publications showing an important role of the endothelium in the mechanism of vasodilation caused by endogenous agents (acetylcholine, bradykinin, substance P, ATP, histamine, thrombin) and pharmacological agents (clonidine, hydralazine, mellitin, calcium ionophore A 23187). The mechanism of the endothelium-dependent vasodilatation is based on the release of the endothelium-derived relaxant factor (EDRF). In 1987-1988 it was shown that in some cases EDRF is NO. The experimental evidence suggests that EDRF (NO) may directly activate guanylate cyclase that results in vascular smooth muscle relaxation due to cAMP accumulation. The possible physiological and pathophysiological significance of the endothelium-dependent vascular responses is discussed.