title: Excitation-contraction coupling in resistance mesenteric arteries: evidence for NKCC1-mediated pathway.
abstract: Bumetanide and other high-ceiling diuretics (HCD) attenuate myogenic tone and contractions of vascular smooth muscle cells (VSMC) triggered by diverse stimuli. HCD outcome may be mediated by their interaction with NKCC1, the only isoform of Na(+), K(+), 2Cl(-) cotransporter expressed in VSMC as well as with targets distinct from this carrier. To examine these hypotheses, we compared the effect of bumetanide on contractions of mesenteric arteries from wild-type and NKCC1 knockout mice. In mesenteric arteries from wild-type controls, 100 microM bumetanide evoked a decrease of up to 4-fold in myogenic tone and contractions triggered by modest [K(+)](o)-induced depolarization, phenylephrine and UTP. These actions of bumetanide were preserved after inhibition of nitric oxide synthase with NG-nitro-l-arginine methyl ester, but were absent in mesenteric arteries from NKCC1(-/-) mice. The data show that bumetanide inhibits VSMC contractile responses via its interaction with NKCC1 and independently of nitric oxide production by endothelial cells.
authors.affiliation: Research Centre, Centre Hospitalier de l'Université de Montréal (CRCHUM - Technopôle Angus), Montreal, PQ, Canada H1W 4A4.
authors.forename: Svetlana V
authors.initials: SV
authors.lastname: Koltsova
authors.forename: Sergei V
authors.initials: SV
authors.lastname: Kotelevtsev
authors.forename: Johanne
authors.initials: J
authors.lastname: Tremblay
authors.forename: Pavel
authors.initials: P
authors.lastname: Hamet
authors.forename: Sergei N
authors.initials: SN
authors.lastname: Orlov
mesh_terms: D000818:Animals; D002034:Bumetanide / Q000494:pharmacology; D004232:Diuretics / Q000494:pharmacology; D008297:Male; D008638:Mesenteric Arteries / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D009129:Muscle Tonus / Q000187:drug effects; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism / Q000502:physiology; D009569:Nitric Oxide / Q000378:metabolism; D049994:Sodium Potassium Chloride Symporter Inhibitors / Q000494:pharmacology; D028021:Sodium-Potassium-Chloride Symporters / Q000502:physiology; D064506:Solute Carrier Family 12, Member 2; D014655:Vascular Resistance / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects*; D014664:Vasodilation / Q000187:drug effects*
chemical_list: D004232:Diuretics; C578878:Slc12a2 protein, mouse; D049994:Sodium Potassium Chloride Symporter Inhibitors; D028021:Sodium-Potassium-Chloride Symporters; D064506:Solute Carrier Family 12, Member 2; D002034:Bumetanide; D009569:Nitric Oxide