resolvin d1 (rvd1) and rvd2 (see resolvins) and maresin 1 are metabolites of the omega 3 fatty acid, docosahexaenoic acid. they are members of the specialized proresolving mediators (spms) class of metabolites that function to resolve diverse inflammatory reactions and diseases in animal models and, it is proposed, in humans. these spms also damp pain perception arising from various inflammation-based causes in animal models. the mechanism behind their pain-dampening effect involves the inhibition of trpa1, probably (in at least certain cases) by an indirect effect wherein they activate another receptor located on neurons or nearby microglia or astrocytes. cmklr1, gpr32, fpr2, and nmda receptors have been proposed to be the receptors through which spms may operate to down-regulate trps and thereby pain perception.