UDP disodium salt is an endogenous P2Y receptor agonist, which specifically activates P2Y6 receptors. It is known that UDP disodium salt can also function as a competitive antagonist at GPR105 (P2Y14) receptors. UDP disodium salt is composed of a pyrophosphate, ribose, and a uracil group, with the pyrophosphate esterified to the C5 of the sugar moiety.