title: p75 neurotrophin receptor regulates agonist-induced pulmonary vasoconstriction.
abstract: A member of the TNF receptor family, the p75 neurotrophin receptor (p75(NTR)) has been previously shown to play a role in the regulation of fibrin deposition in the lung. However, the role of p75(NTR) in the regulation of pulmonary vascular tone in the lung is unknown. In the present study, we evaluated the expression of p75(NTR) in mouse pulmonary arteries and the putative role of p75(NTR) in modulating pulmonary vascular tone and agonist responsiveness using wild-type (WT) and p75(NTR) knockout (p75(-/-)) mice. Our data indicated that p75(NTR) is expressed in both smooth muscle and endothelial cells within the pulmonary vascular wall in WT mice. Pulmonary artery rings from p75(-/-) mice exhibited significantly elevated active tension due to endothelin-1-mediated Ca(2+) influx. Furthermore, the contraction due to capacitative Ca(2+) entry (CCE) in response to phenylephrine-mediated active depletion of intracellular Ca(2+) stores was significantly enhanced compared with WT rings. The contraction due to CCE induced by passive store depletion, however, was comparable between WT and p75(-/-) rings. Active tension induced by serotonin, U-46619 (a thromboxane A(2) analog), thrombin, 4-aminopyridine (a K(+) channel blocker), and high extracellular K(+) in p75(-/-) rings was similar to that in WT rings. Deletion of p75(NTR) did not alter pulmonary vasodilation to sodium nitroprusside (a nitric oxide donor). These data suggest that intact p75(NTR) signaling may play a role in modulating pulmonary vasoconstriction induced by endothelin-1 and by active store depletion.
authors.affiliation: Departments of Medicine, University of California-San Diego, La Jolla, California 92093-0725, USA.
authors.forename: Minlin
authors.initials: M
authors.lastname: Xu
authors.forename: Carmelle V
authors.initials: CV
authors.lastname: Remillard
authors.forename: Benjamin D
authors.initials: BD
authors.lastname: Sachs
authors.forename: Ayako
authors.initials: A
authors.lastname: Makino
authors.forename: Oleksandr
authors.initials: O
authors.lastname: Platoshyn
authors.forename: Weijuan
authors.initials: W
authors.lastname: Yao
authors.forename: Wolfgang H
authors.initials: WH
authors.lastname: Dillmann
authors.forename: Katerina
authors.initials: K
authors.lastname: Akassoglou
authors.forename: Jason X-J
authors.initials: JX
authors.lastname: Yuan
mesh_terms: D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000494:pharmacology; D015761:4-Aminopyridine / Q000494:pharmacology; D000818:Animals; D020013:Calcium Signaling / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D019332:Endothelin-1 / Q000378:metabolism*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D009599:Nitroprusside / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D011651:Pulmonary Artery / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology; D017475:Receptors, Nerve Growth Factor / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D012701:Serotonin / Q000378:metabolism; D013917:Thrombin / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects*; D014662:Vasoconstrictor Agents / Q000378:metabolism / Q000494:pharmacology; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D019332:Endothelin-1; D017475:Receptors, Nerve Growth Factor; C517634:Ngfr protein, mouse; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D012701:Serotonin; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D015761:4-Aminopyridine; D013917:Thrombin; D011188:Potassium