Cytosolic phospholipase A2 in hypoxic pulmonary vasoconstriction

Fumito Ichinose, Roman Ullrich, Adam Sapirstein, Rosemary C. Jones, Joseph V. Bonventre, Charles N. Serhan, Kenneth D. Bloch, Warren M. Zapol

Research output: Contribution to journalArticlepeer-review

Abstract

Cytosolic phospholipase A2 (cPLA2) releases arachidonic acid (AA) from phospholipids in cell membranes. To assess the role of cPLA2 in hypoxic pulmonary vasoconstriction (HPV), we measured the increase in left lung pulmonary vascular resistance (LPVR) before and during hypoxia produced by left main stem bronchus occlusion (LMBO) in mice with and without a targeted deletion of the PLA2g4a gene that encodes cPLA. LMBO increased LPVR in cPLA+/+ mice but not in cPLA-/- mice. cPLA+/+ mice were better able to maintain systemic oxygenation during LMBO than were cPLA-/- mice. Administration of a cPLA2 inhibitor, arachidonyl trifluoromethyl ketone, blocked the LMBO-induced increase in LPVR in wild-type mice, while exogenous AA restored HPV in cPLA-/- mice. Intravenous angiotensin II infusion increased PVR similarly in cPLA+/+ and cPLA-/- mice. Inhibitors of cyclooxygenase or nitric oxide synthase restored HPV in cPLA-/- mice. Breathing 10% oxygen for 3 weeks produced less right ventricular hypertrophy in CPLA-/- than in CPLA+/+ mice, but restored HPV in cPLA-/- mice despite the continued absence of cPLA2 activity. These results indicate that cPLA2 contributes to the murine pulmonary vasoconstrictor response to hypoxia. Augmenting pulmonary vascular tone restores HPV in the absence of cPLA2 activity.

Original languageEnglish (US)
Pages (from-to)1493-1500
Number of pages8
JournalJournal of Clinical Investigation
Volume109
Issue number11
DOIs
StatePublished - 2002
Externally publishedYes

ASJC Scopus subject areas

  • Medicine(all)

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