ABSTRACT
Endogenous cannabinoids (endocannabinoids), which were first identified in the central nervous system, exert cardiovascular actions. The prototypic endocannabinoid, anandamide, which is derived from arachidonic acid, is a vasodilator in the resistance vasculature. However, the mechanisms of vasorelaxation to endocannabinoids are currently unclear but may involve both endothelium-dependent and independent pathways. To date, the mechanisms proposed for the vasorelaxant actions of anandamide have included the release of endothelial autacoids, activation of myoendothelial gap junctions, activation of the sodium pump, activation of potassium channels, inhibition of calcium channels, and activation of vanilloid receptors leading to the release of sensory neurotransmitters. The vasodilator actions of endocannabinoids have been implicated in the hypotension associated with both septic and hemorrhagic shock, but their physiological significance remains to be determined.
