P2 receptors are functionally expressed along the distal renal tubule and their activation regulates Na+, K+ and H2O transport1,2. Strong evidence highlights a crucial role of the P2Y2 receptor in this segment. Activation of luminal (and basolateral) P2Y2 receptors inhibit ENaC-mediated Na+ absorption3 and global KO of this receptor causes augmented renal Na+ and H2O absorption and increased systemic blood pressure 4. In this study we used the isolated perfused tubule technique together with fluo-4 intracellular Ca2+ imaging in P2Y2 WT and KO mice cortical collecting ducts to more comprehensively search for functionally relevant expression of luminal and basolateral P2 receptors. We find/confirm that luminal and basolateral ATP/UTP applied from either sides of the epithelium are potent agonists to trigger [Ca2+]i increases. (WT % fluo-4 increase, luminal UTP: 56±9 and luminal ATP: 47±10; basolateral UTP: 32±7 and basolateral ATP: 26±4, n=5). In KO tubules the luminal and basolateral UTP effect were absent (KO % fluo-4 increase, luminal UTP: 3±1; basolateral UTP: 0±0, n=14). Intriguingly, despite the ineffectiveness of luminal UTP in P2Y2 KO tubules, luminal ATP continued to trigger [Ca2+]i increases, which amounted to about 50% of the WT luminal ATP response (KO % fluo-4 increase, luminal ATP: 19±5) . Basolateral ATP-triggered [Ca2+]i responses were reduced in KO tubules (KO % fluo-4 increase, ATP: 16±2). These results define that mouse cortical collecting ducts express luminal and basolateral P2Y2 receptors. In addition, yet another luminal P2 receptor is present in this segment. Based on literature a P2X type receptor is suggested. The basolateral membrane is likewise equipped with at least one other P2 receptor, its nature remains to be established. These results extend the current state of knowledge of these receptors in the collecting duct and demand further in depth investigation of their functional relevance in salt and water handling.