title: Role of TRPC1 and TRPC3 channels in contraction and relaxation of mouse thoracic aorta.
abstract: OBJECTIVE
  Canonical transient receptor potential (TRPC) channels modulate membrane potential and intracellular Ca(2+). We examined the role of TRPC1 and TRPC3 channels in vasocontraction and relaxation in mouse aorta.
  
  
  METHODS
  Vasocontraction and relaxation of aorta from wild-type (WT), TRPC1 KO and TRPC3 knockout (KO) mice were measured for phenylephrine (Phe) and carbachol (CCh). Intracellular Ca(2+) was measured in primary aorta endothelial cells (EC) and whole cell K(+) current in freshly isolated smooth muscle cells (SMC).
  
  
  CONCLUSIONS
  TRPC1 KO aorta showed increased vasocontraction to Phe compared to WT and TRPC3 KO aorta due to diminished role of BK(Ca) channels. BK(Ca) mRNA (aorta) and whole cell current (SMC) were reduced versus WT. Contraction in WT aorta was increased to TRPC1 KO level by BK(Ca) channel inhibition. Relaxation to CCh was reduced in TRPC1 KO and TRPC3 KO aortas with concomitant reduction in EC Ca(2+) response. Pyr3 (TRPC3 blocker) reduced the Ca(2+) response to CCh in EC from WT, but not TRPC3 KO mice. In summary, TRPC1 attenuates receptor-mediated contraction through activation and/or expression of SMC BK(Ca) channels while TRPC3 does not contribute to receptor-mediated constriction. Both TRPC1 and TRPC3 participate in EC Ca(2+) influx and vasorelaxation of aorta.
authors.affiliation: Department of Anesthesiology, Baylor College of Medicine, Houston, TX 77030, USA.
authors.forename: M Y
authors.initials: MY
authors.lastname: Kochukov
authors.forename: A
authors.initials: A
authors.lastname: Balasubramanian
authors.forename: R C
authors.initials: RC
authors.lastname: Noel
authors.forename: S P
authors.initials: SP
authors.lastname: Marrelli
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits / Q000037:antagonists & inhibitors / Q000378:metabolism; D008564:Membrane Potentials; D051379:Mice; D018345:Mice, Knockout; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism; D011188:Potassium / Q000378:metabolism; D026902:Potassium Channel Blockers / Q000494:pharmacology; D050052:TRPC Cation Channels / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D014661:Vasoconstriction / Q000187:drug effects; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: C530995:BKCa protein, mouse; D051037:Large-Conductance Calcium-Activated Potassium Channel alpha Subunits; D026902:Potassium Channel Blockers; D050052:TRPC Cation Channels; C104603:TRPC3 cation channel; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; C096351:transient receptor potential cation channel, subfamily C, member 1; D011188:Potassium; D002118:Calcium