The Cannabinoid System-A Brief Review

Abstract A9-THC, the main psychoactive cannabinoid from the Cannabis plant, binds to specific binding sites in humans, which are situated in membranes of nerve and several other cells in both the central nervous system and peripheral organs. Evidence for the existence of the specific action of cannabinoids was presented in the late 1980s. Depending on the kind of cells, on dose, and on the state of the body, activation of cannabinoid receptors (CB) may cause a multitude of effects including euphoria, anxiety, dry mouth, muscle relaxation, hunger and pain reduction. In 1992 the first endogenous substance that binds to CB receptors, which causes similar effects as THC was detected. Five of these endo-cannabinoids and two subtypes of cannabinoid receptors are known so far, constituting the endogenous cannabinoid system in humans and other animals. Several approaches are under investigation to influence the cannabinoid system with therapeutic intent, including agonistic and antagonistic actions at CB receptors and modulation of endocanna-binoid concentrations.