title: Nitric-oxide synthase knockout modulates Ca²⁺-sensing receptor expression and signaling in mouse mesenteric arteries.
abstract: Extracellular calcium (Ca²⁺(e))-induced relaxation of isolated, phenylephrine (PE)-contracted mesenteric arteries is dependent on an intact perivascular sensory nerve network that expresses the Ca²⁺-sensing receptor (CaSR). Activation of the receptor stimulates an endocannabinoid vasodilator pathway, which is dependent on cytochrome P450 and phospholipase A₂ but largely independent of the endothelium. In the present study, we determined the role of nitric oxide (NO) in perivascular nerve CaSR-mediated relaxation of PE-contracted mesenteric resistance arteries isolated from mice. Using automated wire myography, we studied the effects of NO synthase (NOS) gene knockout (NOS(-/-)) and pharmacologic inhibition of NOS on Ca²⁺(e)-induced relaxation of PE-contracted arteries. Endothelial NOS knockout (eNOS(-/-)) upregulates but neuronal NOS knockout (nNOS(-/-)) downregulates CaSR expression. NOS(-/-) reduced maximum Ca²⁺(e)-induced relaxation with no change in EC₅₀ values, with eNOS(-/-) having the largest effect. The responses of vessels to calindol and Calhex 231 indicate that the CaSR mediates relaxation. L-N⁵-(1-iminoethyl)-ornithine reduced Ca²⁺(e)-induced relaxation of PE-contracted arteries from C57BL/6 control mice by ≈38% but had a smaller effect in vessels from eNOS(-/-) mice. 7-Nitroindazole had no significant effect on relaxation of arteries from NOS(-/-) mice, but both N(G)-nitro-L-arginine methylester and N(G)-monomethyl-L-arginine significantly reduced the relaxation maxima in all groups. Interestingly, the nNOS-selective inhibitor S-methyl-L-thiocitrulline significantly increased the EC₅₀ value by ≈60% in tissues from C57BL/6 mice but reduced the maximum response by ≈80% in those from nNOS(-/-) mice. Ca²⁺-activated big potassium channels play a major role in the process, as demonstrated by the effect of iberiotoxin. We conclude that CaSR signaling in mesenteric arteries stimulates eNOS and NO production that regulates Ca²⁺(e)-induced relaxation.
authors: Cardiovascular & Metabolic Diseases Research Program, Julius L. Chambers Biomedical/Biotechnology Research Institute, North Carolina Central University, 700 George Street, Durham, NC 27707, USA. eawumey@nccu.edu
authors: Emmanuel M
authors: EM
authors: Awumey
authors: Lakeesha E
authors: LE
authors: Bridges
authors: Cicely L
authors: CL
authors: Williams
authors: Debra I
authors: DI
authors: Diz
mesh_terms: D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020013:Calcium Signaling / Q000187:drug effects; D015536:Down-Regulation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D008638:Mesenteric Arteries / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009415:Nerve Net / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D009569:Nitric Oxide / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052248:Nitric Oxide Synthase Type I / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D052250:Nitric Oxide Synthase Type III / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D044169:Receptors, Calcium-Sensing / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015854:Up-Regulation; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000037:antagonists & inhibitors / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D002121:Calcium Channel Blockers; D004791:Enzyme Inhibitors; D009419:Nerve Tissue Proteins; D044169:Receptors, Calcium-Sensing; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009569:Nitric Oxide; D052248:Nitric Oxide Synthase Type I; D052250:Nitric Oxide Synthase Type III; C496321:Nos1 protein, mouse; C496315:Nos3 protein, mouse
references: Eur J Biochem. 2003 Jun;270(12):2680-8
references: 12787035
references: Circulation. 2009 May 26;119(20):2656-62
references: 19433760
references: J Vasc Res. 2011;48(1):1-10
references: 20606466
references: Bioorg Med Chem Lett. 2004 Jun 21;14(12):3345-9
references: 15149704
references: Am J Physiol. 1998 May;274(5):H1655-61
references: 9612376
references: J Vis Exp. 2011 Sep 22;(55):
references: 21969063
references: Biochem Biophys Res Commun. 2012 Feb 24;418(4):770-3
references: 22310712
references: Life Sci. 1999;64(10):887-94
references: 10096439
references: Am J Physiol Cell Physiol. 2007 May;292(5):C1895-905
references: 17267550
references: Hypertension. 1997 Dec;30(6):1431-9
references: 9403564
references: Circ Res. 2005 Aug 19;97(4):391-8
references: 16037572
references: Hypertension. 2002 Feb;39(2):251-7
references: 11847193
references: J Pharmacol Exp Ther. 1999 Apr;289(1):245-50
references: 10087011
references: Circulation. 2005 Feb 15;111(6):796-803
references: 15699263
references: Circ Res. 2007 Aug 31;101(5):493-502
references: 17641230
references: J Vasc Res. 2009;46(1):73-82
references: 18577871
references: J Biol Chem. 1996 Aug 9;271(32):19537-45
references: 8702647
references: J Physiol Pharmacol. 2006 Nov;57 Suppl 11:133-44
references: 17244945
references: Cardiovasc Res. 2009 Feb 1;81(2):260-8
references: 18852253
references: J Biol Chem. 1998 Sep 4;273(36):23605-10
references: 9722601
references: Am J Hypertens. 2003 Sep;16(9 Pt 1):771-6
references: 12944037
references: Am J Physiol. 1999 Mar;276(3):H1035-42
references: 10070089
references: J Cell Mol Med. 2007 Sep-Oct;11(5):923-34
references: 17979874
references: Br J Pharmacol. 2005 Feb;144(4):449-58
references: 15655530
references: Hypertension. 2001 Oct;38(4):833-9
references: 11641295
references: J Hepatol. 1996 Apr;24(4):487-90
references: 8738736
references: Arterioscler Thromb Vasc Biol. 2006 Jun;26(6):1215-25
references: 16543495
references: J Membr Biol. 2000 Jun 1;175(3):203-12
references: 10833530
references: Eur J Pharmacol. 1996 Sep 19;312(1):63-8
references: 8891579
references: J Pharmacol Toxicol Methods. 2000 Sep-Oct;44(2):395-407
references: 11325582
references: Am J Physiol Heart Circ Physiol. 2008 May;294(5):H2363-70
references: 18375719
references: Cell Physiol Biochem. 2008;22(5-6):413-22
references: 19088423
references: J Biol Chem. 2005 Nov 4;280(44):37013-20
references: 16135510
references: Nephrol Dial Transplant. 2001 Feb;16(2):218-21
references: 11158390
references: Physiol Rev. 2001 Jan;81(1):239-297
references: 11152759
references: Br J Pharmacol. 1998 Dec;125(7):1397-404
references: 9884066