The role of serotonin in cardiovascular diseases and their treatment.

Serotonin (5HT), discovered in the 1950s, has been the subject of renewed interest for several years, in particular due to the subdivision of 5HT receptors into various types. Concomitantly, several more or less selective agonists and antagonists for these various receptor subtypes have been developed. Although the physiologic relevance of 5HT remains largely unknown, its role in certain pathologic processes is widely accepted. Certain symptoms of the carcinoid syndrome, thromboembolic processes at the level of the microcirculation, and possibly also coronary spasm and peripheral vascular disease are likely to be associated, at least in part, with endogenous 5HT and serotonergic mechanisms. However, a primary and causative role for such mechanisms in essential hypertension seems unlikely. The blockade of peripheral 5HT2 receptors with drugs may offer advantages, in particular in those disorders where an interaction between predamaged blood vessels and platelets is involved. Such a therapeutic approach seems to be a more generally applicable principle than the lowering of blood pressure as such, which appears not to be a general phenomenon provoked by 5HT2-receptor blockade.