UDP is the diphosphate of the nucleoside uridine. It is a specific agonist of the P2Y purinoceptor P2Y₆(EC₅₀= 13 nM for human P2Y₆), stimulating the production of inflammatory mediators, phagocytosis, and vasoconstriction.^1,2,3,4,5,6UDP also acts as an antagonist of P2Y₁₄, whose agonists include UDP-glucose , UDP-galactose, and UDP-glucuronic acid.^1,2

1.Jacobson, K.A., Ivanov, A.A., de Castro, S., et al.Development of selective agonists and antagonists of P2Y receptorsPurinergic Signal.5(1)75-89(2009) 2.Abbracchio, M.P., Burnstock, G., Boeynaems, J.M., et al.International Union of Pharmacology LVIII: Update on the P2Y G protein-coupled nucleotide receptors: From molecular mechanisms and pathophysiology to therapyPharmacological Reviews58(3)281-341(2006) 3.Garcia, R.A., Yan, M., Search, D., et al.P2Y6 receptor potentiates pro-inflammatory responses in macrophages and exhibits differential roles in atherosclerotic lesion developmentPLoS One9(10)1-13(2014) 4.Inoue, K.UDP facilitates microglial phagocytosis through P2Y6 receptorsCell Adhesion & Migration1(3)131-132(2007) 5.Besada, P., Shin, D.H., Costanzi, S., et al.Structure-activity relationships of uridine 5’-diphosphate analogues at the human P2Y6 receptorJournal of Medicinal Chemistry49(18)5532-5543(2006) 6.Mitchell, C., Syed, N., Tengah, A., et al.Identification of contractile P2Y1, P2Y6, and P2Y12 receptors in rat intrapulmonary artery using selective ligandsJournal of Pharmacology and Experimental Therapeutics343(3)755-762(2012)