Sigma receptors: from discovery to highlights of their implications in the cardiovascular system.

Sigma receptors are the targets of many ligands, of which some (the haloperidol for instance) are psychoactive, and of substances known to have antiarrhythmic effects (amiodarone and clofilium). They are involved in a variety of cardiovascular functions, such as the regulation of cardiac contractility and rhythm and the regulation of coronary and peripheral arterial vasomotricity. This short review will focus on some aspects regarding the ligands, the binding sites, the intracellular coupling and the cardiovascular functions of these enigmatic receptors.