title: Myogenic tone in mouse mesenteric arteries: evidence for P2Y receptor-mediated, Na(+), K (+), 2Cl (-) cotransport-dependent signaling.
abstract: This study examines the action of agonists and antagonists of P2 receptors on mouse mesenteric artery contractions and the possible involvement of these signaling pathways in myogenic tone (MT) evoked by elevated intraluminal pressure. Both ATP and its non-hydrolyzed analog alpha,beta-ATP triggered transient contractions that were sharply decreased in the presence of NF023, a potent antagonist of P2X(1) receptors. In contrast, UTP and UDP elicited sustained contractions which were suppressed by MRS2567, a selective antagonist of P2Y(6) receptors. Inhibition of Na(+), K(+), 2Cl(-) cotransport (NKCC) with bumetanide led to attenuation of contractions in UTP- but not ATP-treated arteries. Both UTP-induced contractions and MT were suppressed by MRS2567 and bumetanide but were insensitive to NF023. These data implicate a P2Y(6)-mediated, NKCC-dependent mechanism in MT of mesenteric arteries. The action of heightened intraluminal pressure on UTP release from mesenteric arteries and its role in the triggering of P2Y(6)-mediated signaling should be examined further.
authors.affiliation: Research Centre, University of Montreal Hospital Centre (CRCHUM), Technopôle Angus, Moscow, Russia.
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Koltsova
authors.forename: Georgy V
authors.initials: GV
authors.lastname: Maximov
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Kotelevtsev
authors.forename: Julie L
authors.initials: JL
authors.lastname: Lavoie
authors.forename: Johanne
authors.initials: J
authors.lastname: Tremblay
authors.forename: Ryszard
authors.initials: R
authors.lastname: Grygorczyk
authors.forename: Pavel
authors.initials: P
authors.lastname: Hamet
authors.forename: Sergei N
authors.initials: SN
authors.lastname: Orlov