Uridine-5'-diphosphate disodium salt is a potent, selective P2Y6 receptor native agonist (EC50=300 nM; pEC50=6.52) and a potent P2Y14 antagonist (pEC50=7.28). Uridine-5'-diphosphate disodium salt, an endogenous metabolite, catalyzes the glucuronidation of a wide array of substrates and is used in nucleic acid (RNA) biosynthesis.