Abstract
The relationship between pulmonary arterial pressure (Ppa) and blood (Q) was determined during normoxia and hypoxia in ventilated pig lungs perfused in situ with the animal's own blood. Hypoxia shifted the Ppa-Q relationship to the right and decreased its slope, indicating pulmonary vasoconstriction. Carbon monoxide (11.5% in the inspired gas) and metyrapone ditartrate (10 mg/min into the perfusate) caused vasodilation when oxygenation was normal and reduced the vasoconstriction caused by hypoxia. Since the only pharmacological property CO and metyrapone are thought to have in common at the concentrations employed is the ability to bind to the heme iron of cytochrome P-450, these results are consistent with the hypothesis that desaturation of this cytochrome leads to pulmonary vasoconstriction. Prostaglandin F2alpha, infused into the pulmonary artery at 0.01 mg/min, when oxygenation was normal, had effects on the Ppa-Q relationship similar to those of hypoxia. The F2alpha response was also reduced by CO and metyrapone, suggesting either that P-450 was involved in the F2alpha response or that CO and metyrapone were toxic to pulmonary vascular smooth muscle. Proadifen hydrochloride (1 mg/min), which is thought to bind to the protein moiety of P-450 also reduced the hypoxic response, but was a vasoconstrictor during normoxia and did not affect the F2alpha response.
Publisher
Ovid Technologies (Wolters Kluwer Health)
Subject
Cardiology and Cardiovascular Medicine,Physiology
Reference37 articles.
1. Pulmonary vasomotor responses of isolated perfused cat lungs to anoxia
2. Duke H Killick E: The effects of the inhalation of various gas mixtures on the pulmonary blood vessels (abstr). Proceedings: XVIII International Physiological Congress 1950 p l 8 2
3. CARBON MONOXIDE ANOXEMIA
4. Carbon monoxide;Lilienthal J;Pharmacol Rev,1950
5. The reaction of cytochrome oxidase with carbon monoxide;Ball E;J Biol Chem,1951
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