Cloning of the rat p2u receptor and its potential role in coronary vasodilation. G[diaeresis]odecke, Stefanie, Ulrich K. M. Decking, Axel G[diaeresis]odecke, and J[umlaut]urgen Schrader. Institut f[umlaut]ur Herz- und Kreislaufphysiologie, Heinrich -Heine-Universit[umlaut]at, Universit[umlaut]atsstr. 1, D-40225 D[umlaut]usseldorf, Federal Republic of Germany
APStracts 2:0298C, 1995.
We cloned and sequenced the cDNA as well as the genomic DNA of the P2u receptor gene from the rat. The coding region of the gene is not interrupted by introns. P2u is expressed in a variety of rat organs with pronounced differences of expression intensities. Highest expression was found in liver and testis, while no expression could be detected in the brain. High P2u expression was found in primary microvascular endothelial cells from the rat heart, but not in cardiac myocytes. By in situ analysis we localised P2u expression in epithelial cells of esophagus and bronchi. Functional analysis revealed that in isolated perfused rat hearts, the P2u ligands UTP (uridine 5'-triphosphate) and ATP induce a pronounced vasodilation of coronary blood vessels. In contrast, UMP (uridine 5'-monophosphate) and uridine, the degradative products of UTP, act as potent vasoconstrictors. Our experiments suggest that in the rat heart, endothelial P2u receptors are involved in the ATP/UTP mediated vasodilation of coronary blood vessels. 

Received 27 March 1995; accepted in final form 8 August 1995.
APS Manuscript Number C168-5.
Article publication pending Am. J. Physiol. (Cell Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 24 August 1995.