Receptor
The GPR32 protein is a G protein coupled receptor although the specific G protein subtypes which it activates has not yet been reported. GPR32 is expressed in human blood neutrophils, certain types of blood lymphocytes (i.e. activated CD8+ cells, CD4+ T cells, and T helper 17 cells), tissue macrophages, small airway epithelial cells, and adipose tissue. When expressed in Chinese hamster ovary cells, GPR32 inhibits the Cyclic adenosine monophosphate signaling pathway under both baseline and forskolin-stimulated conditions indicating that it is a member of the class of orphan G protein coupled receptors that possesses constitutive signaling activity.
At least 6 members of the D series of resolvins (RvDs) viz., RvD1, RvD2m AT-RVD1, RvD3, AT-RvD3, and RvD5, activate their target cells through this receptor; these results have led to naming GPR32 the RVD1 receptor (see resolvin mechanisms of action). RvDs are members of the specialized proresolving mediators (SPM) class of polyunsaturated fatty acid metabolites. RVDs are metabolites of the omega-3 fatty acid, docosahexaenoic acid (DHA), and, along with other SRMs contribute to the inhibition and resolution of a diverse range of inflammation and inflammation-related responses as well as to the healing of these inflammatory lesions in animals and humans. The metabolism of DHA to RVD's and the activation of GPR32 by these RVD's are proposed to be one mechanism by which omega-3 fatty acids may ameliorate inflammation as well as various inflammation-based and other diseases.