Biomaterial Database

Selective pulmonary vasodilation by inhaled nitric oxide is due to hemoglobin inactivation. 1993

S Rimar, and C N Gillis

Department of Anesthesiology, Yale University School of Medicine, New Haven, Conn. 06510.

BACKGROUND Inhaled nitric oxide gas selectively decreases pulmonary artery pressure without affecting systemic arterial pressure. To determine if the selective pulmonary vasodilating effect of inhaled nitric oxide gas is due to inactivation by hemoglobin, we studied the ability of whole blood to inhibit the vasodilator activity of effluent from isolated lungs exposed to inhaled nitric oxide. RESULTS The effluent from ventilated, Krebs-perfused rabbit lungs was passed directly over 3- to 4-mm rabbit aortic rings. Inhaled nitric oxide (150 ppm for 3 minutes) reduced pulmonary perfusion pressure, elevated by a continuous infusion of U46619, by 35 +/- 7% (mean +/- SEM, n = 5). Lung effluent from this series of experiments caused 40 +/- 13% relaxation of phenylephrine-preconstricted aortic rings. When blood was added to the combined lung/ring perfusion cascade (final hemoglobin concentration, 1 g/dL), inhaled nitric oxide again significantly reduced pulmonary perfusion pressure, but the effluent now failed to relax the aortic rings (30 +/- 6% [control] versus 1.5 +/- 1% [blood]). Both reduction in pulmonary perfusion pressure and relaxation of the rings during nitric oxide exposure were unchanged from control values after discontinuing the blood infusion. CONCLUSIONS The presence of hemoglobin, even in extremely small amounts, restricts the vasodilating effect of inhaled nitric oxide gas to the pulmonary circulation.

UI	MeSH Term	Description	Entries
D008297	Male		Males
D009569	Nitric Oxide	A free radical gas produced endogenously by a variety of mammalian cells, synthesized from ARGININE by NITRIC OXIDE SYNTHASE. Nitric oxide is one of the ENDOTHELIUM-DEPENDENT RELAXING FACTORS released by the vascular endothelium and mediates VASODILATION. It also inhibits platelet aggregation, induces disaggregation of aggregated platelets, and inhibits platelet adhesion to the vascular endothelium. Nitric oxide activates cytosolic GUANYLATE CYCLASE and thus elevates intracellular levels of CYCLIC GMP.	Endogenous Nitrate Vasodilator,Mononitrogen Monoxide,Nitric Oxide, Endothelium-Derived,Nitrogen Monoxide,Endothelium-Derived Nitric Oxide,Monoxide, Mononitrogen,Monoxide, Nitrogen,Nitrate Vasodilator, Endogenous,Nitric Oxide, Endothelium Derived,Oxide, Nitric,Vasodilator, Endogenous Nitrate
D010477	Perfusion	Treatment process involving the injection of fluid into an organ or tissue.	Perfusions
D011652	Pulmonary Circulation	The circulation of the BLOOD through the LUNGS.	Pulmonary Blood Flow,Respiratory Circulation,Circulation, Pulmonary,Circulation, Respiratory,Blood Flow, Pulmonary,Flow, Pulmonary Blood,Pulmonary Blood Flows
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
D001769	Blood	The body fluid that circulates in the vascular system (BLOOD VESSELS). Whole blood includes PLASMA and BLOOD CELLS.
D006454	Hemoglobins	The oxygen-carrying proteins of ERYTHROCYTES. They are found in all vertebrates and some invertebrates. The number of globin subunits in the hemoglobin quaternary structure differs between species. Structures range from monomeric to a variety of multimeric arrangements.	Eryhem,Ferrous Hemoglobin,Hemoglobin,Hemoglobin, Ferrous
D000280	Administration, Inhalation	The administration of drugs by the respiratory route. It includes insufflation into the respiratory tract.	Drug Administration, Inhalation,Drug Administration, Respiratory,Drug Aerosol Therapy,Inhalation Drug Administration,Inhalation of Drugs,Respiratory Drug Administration,Aerosol Drug Therapy,Aerosol Therapy, Drug,Drug Therapy, Aerosol,Inhalation Administration,Administration, Inhalation Drug,Administration, Respiratory Drug,Therapy, Aerosol Drug,Therapy, Drug Aerosol
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001013	Aorta, Thoracic	The portion of the descending aorta proceeding from the arch of the aorta and extending to the DIAPHRAGM, eventually connecting to the ABDOMINAL AORTA.	Aorta, Ascending,Aorta, Descending,Aortic Arch,Aortic Root,Arch of the Aorta,Descending Aorta,Sinotubular Junction,Ascending Aorta,Thoracic Aorta,Aortic Roots,Arch, Aortic,Ascending Aortas,Junction, Sinotubular,Root, Aortic,Sinotubular Junctions