title: NTPDase1 (CD39) controls nucleotide-dependent vasoconstriction in mouse.
abstract: OBJECTIVE
  Extracellular nucleotides are vasoactive molecules. The concentrations of these molecules are regulated by ectonucleotidases. In this study, we investigated the role of the blood vessel ectonucleotidase NTPDase1, in the vasoconstrictor effect of nucleotides using Entpd1(-/-) mice.
  
  
  RESULTS
  Immunofluorescence, enzyme histochemistry, and HPLC analysis were used to evaluate both NTPDase expression and activity in arteries and isolated vascular smooth muscle cells (VSMCs). Vascular reactivity was evaluated in vitro and mean arterial blood pressure was recorded in anesthetized mice after nucleotide i.v. infusion. Expression of nucleotide receptors in VSMCs was determined by RT-PCR. Entpd1(-/-) mice displayed a dramatic deficit of nucleotidase activity in blood vessel wall in situ and in VSMCs in comparison to control mice. In aortic rings from Entpd1(-/-) mice, UDP and UTP induced a potent and long-lasting constriction contrasting with the weak response obtained in wild-type rings. This constriction occurred through activation of P2Y(6) receptor and was independent of other uracil nucleotide-responding receptors (P2Y(2) and P2Y(4)). UDP infusion in vivo increased blood pressure and this effect was potentiated in Entpd1(-/-) mice. In addition, pressurized mesenteric arteries from Entpd1(-/-) mice displayed an enhanced myogenic response, consistent with higher local concentrations of endogenously released nucleotides. This effect was inhibited by the P2 receptor antagonist RB-2.
  
  
  CONCLUSIONS
  NTPDase1 is the major enzyme regulating nucleotide metabolism at the surface of VSMCs and thus contributes to the local regulation of vascular tone by nucleotides.
authors.affiliation: Centre de Recherche en Rhumatologie et Immunologie, Université Laval, Québec, QC, Canada G1V 4G2.
authors.forename: Gilles
authors.initials: G
authors.lastname: Kauffenstein
authors.forename: Annick
authors.initials: A
authors.lastname: Drouin
authors.forename: Nathalie
authors.initials: N
authors.lastname: Thorin-Trescases
authors.forename: Hélène
authors.initials: H
authors.lastname: Bachelard
authors.forename: Bernard
authors.initials: B
authors.lastname: Robaye
authors.forename: Pedro
authors.initials: P
authors.lastname: D'Orléans-Juste
authors.forename: François
authors.initials: F
authors.lastname: Marceau
authors.forename: Eric
authors.initials: E
authors.lastname: Thorin
authors.forename: Jean
authors.initials: J
authors.lastname: Sévigny
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D001011:Aorta / Q000502:physiology; D001081:Apyrase / Q000502:physiology*; D001794:Blood Pressure / Q000187:drug effects; D066298:In Vitro Techniques; D051379:Mice; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000201:enzymology; D032389:Myocytes, Smooth Muscle / Q000201:enzymology; D009711:Nucleotides / Q000494:pharmacology*; D011983:Receptors, Purinergic / Q000032:analysis / Q000502:physiology; D014530:Uridine Diphosphate / Q000494:pharmacology; D014661:Vasoconstriction / Q000187:drug effects*
chemical_list: D015703:Antigens, CD; D009711:Nucleotides; D011983:Receptors, Purinergic; D014530:Uridine Diphosphate; D001081:Apyrase; C067869:CD39 antigen