Hypoxic pulmonary vasoconstriction is not endothelium dependent.
Feline intrapulmonary arteries (mean diameter, 0.9 mm) were equilibrated in Earle's solution at constant tension in a chamber bubbled with an hyperoxic gas mixture (30% oxygen, 5% carbon dioxide, balance nitrogen). The endothelium was removed from half the vessels by gentle rubbing. The isometric response to the addition of acetylcholine (1*10(-6) M) was dilator in the vessels with endothelium and constrictor in those without endothelium. Intermittent exposure to a hypoxic gas mixture (0% oxygen, 5% carbon dioxide, balance nitrogen) for 20 min with five repetitions demonstrated sustained constrictor responses in the presence or absence of endothelium. Endothelial cells are, therefore, not required for the mediation of hypoxic pulmonary vasoconstriction.
Marshall
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C
Center for Anesthesia Research, University of Pennsylvania, Philadelphia 19104-4283.
Marshall
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BE
D000818:Animals; D002415:Cats; D004730:Endothelium, Vascular / Q000503:physiopathology*; D005260:Female; D000860:Hypoxia / Q000503:physiopathology*; D011651:Pulmonary Artery / Q000503:physiopathology; D011652:Pulmonary Circulation; D014661:Vasoconstriction