Expression and function of rat urothelial P2Y receptors

Departments of 1 Medicine and 2 Pharmacology, University of Pittsburgh, Pittsburgh, Pennsylvania; and 3 Roche, Biochemical Pharmacology Group, Inflammation Discovery, Palo Alto, California Submitted 12 August 2006 ; accepted in final form 17 January 2008 The control and regulation of the lower urinary tract are partly mediated by purinergic signaling. This study investigated the distribution and function of P2Y receptors in the rat urinary bladder. Application of P2Y agonists to rat urothelial cells evoked increases in intracellular calcium; the rank order of agonist potency (pEC 50 ± SE) was ATP (5.10 ± 0.07) > UTP (4.91 ± 0.14) > UTP S (4.61 ± 0.16) = ATP S (4.70 ± 0.05) > 2-methylthio adenosine 5'-diphosphate = 5'-( N -ethylcarboxamido)adenosine = ADP (