title: Endothelial Connexin37 and Connexin40 participate in basal but not agonist-induced NO release.
abstract: BACKGROUND
  Connexin37 (Cx37) and Cx40 are crucial for endothelial cell-cell communication and homeostasis. Both connexins interact with endothelial nitric oxide synthase (eNOS). The exact contribution of these interactions to the regulation of vascular tone is unknown.
  
  
  RESULTS
  Cx37 and Cx40 were expressed in close proximity to eNOS at cell-cell interfaces of mouse aortic endothelial cells. Absence of Cx37 did not affect expression of Cx40 and a 50 % reduction of Cx40 in Cx40(+/-) aortas did not affect the expression of Cx37. However, absence of Cx40 was associated with reduced expression of Cx37. Basal NO release and the sensitivity for ACh were decreased in Cx37(-/-) and Cx40(-/-) aortas but not in Cx40(+/-) aortas. Moreover, ACh-induced release of constricting cyclooxygenase products was present in WT, Cx40(-/-) and Cx40(+/-) aortas but not in Cx37(-/-) aortas. Finally, agonist-induced NO-dependent relaxations and the sensitivity for exogenous NO were not affected by genotype.
  
  
  CONCLUSIONS
  Cx37 is more markedly involved in basal NO release, release of cyclooxygenase products and the regulation of the sensitivity for ACh as compared to Cx40.
authors.affiliation: Department of Pathology and Immunology, University of Geneva, 6th floor, 1 Rue Michel-Servet, 1211, Geneva, Switzerland. merlijn.meens@unige.ch.|Department of Medical Specialties - Cardiology, University of Geneva, Geneva, Switzerland. merlijn.meens@unige.ch.
authors.forename: Merlijn J
authors.initials: MJ
authors.lastname: Meens
authors.affiliation: Department of Medicine, University Hospital, CHUV, Lausanne, Switzerland.
authors.forename: Florian
authors.initials: F
authors.lastname: Alonso
authors.affiliation: Department of Medicine, University Hospital, CHUV, Lausanne, Switzerland.
authors.forename: Loïc
authors.initials: L
authors.lastname: Le Gal
authors.affiliation: Department of Pathology and Immunology, University of Geneva, 6th floor, 1 Rue Michel-Servet, 1211, Geneva, Switzerland.|Department of Medical Specialties - Cardiology, University of Geneva, Geneva, Switzerland.
authors.forename: Brenda R
authors.initials: BR
authors.lastname: Kwak
authors.affiliation: Department of Medicine, University Hospital, CHUV, Lausanne, Switzerland.
authors.forename: Jacques-Antoine
authors.initials: JA
authors.lastname: Haefliger
mesh_terms: D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D001011:Aorta / Q000166:cytology / Q000502:physiology*; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D004730:Endothelium, Vascular / Q000166:cytology* / Q000502:physiology; D017353:Gene Deletion; D005786:Gene Expression Regulation; D005838:Genotype; D051379:Mice; D008810:Mice, Inbred C57BL; D009569:Nitric Oxide / Q000819:agonists / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000378:metabolism; D014661:Vasoconstriction; D014664:Vasodilation; D000097003:Gap Junction alpha-5 Protein; D000097006:Gap Junction alpha-4 Protein
chemical_list: D000109:Acetylcholine; D017630:Connexins; D009569:Nitric Oxide; D052250:Nitric Oxide Synthase Type III; D000097003:Gap Junction alpha-5 Protein; D000097006:Gap Junction alpha-4 Protein