Inhaled nitric oxide: Dose response and the effects of blood in the isolated rat lung

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Journal of Applied Physiology (1985); (United States)

DOI:https://doi.org/10.1097/00132586-199312000-00062· OSTI ID:5100842

Rich, G F; Roos, C M; Anderson, S M; Urich, D C; Daugherty, M O; Johns, R A ^[1]

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1. Univ. of Virginia Health Sciences Center, Charlottesville, VA (United States)

Inhaled nitric oxide (NO) is a vasodilator selective to the pulmonary circulation. Using isolated rat lungs, the authors determined the dose-response relationship of NO and the role of blood in mediating pulmonary vasodilation and selectivity. Inhaled 20, 50, 100, and 1,000 ppm NO attenuated (P < 0.001) hypoxic pulmonary vasoconstriction by 16.1 [+-] 4.9, 22.6 [+-] 6.8, 28.4 [+-] 3.5, and 69.3 [+-] 4.2%, respectively. Inhaled 13, 34, 67, and 670 ppm NO attenuated the increase in pulmonary arterial pressure secondary to angiotensin II more (P < 0.001) in Greenberg-Bohr buffer- (GB) than in blood-perfused lungs (51.7 [+-] 0.0, 71.9 [+-] 8.9, 78.2 [+-] 5.3, and 91.9 [+-] 2.1% vs. 14.3 [+-] 4.2, 23.8 [+-] 4.6, 28.4 [+-] 3.8, and 55.5 [+-] 5.9%, respectively). Samples from GB- but not blood-perfused lungs contained NO (93.0 [+-] 26.3 nM). Intravascular NO attenuated the response to angiotensin II more (P < 0.001) in GB- (with and without plasma) than in blood- (hematocrit = 41 and 5%) perfused lungs (75.6 [+-] 6.4 and 70.9 [+-] 4.8% vs. 22.2 [+-] 2.4 and 39.4 [+-] 7.6%). In conclusion, inhaled NO produces reversible dose-dependent pulmonary vasodilation over a large range of concentrations. Inhaled NO enters the circulation, but red blood cells prevent systematic vasodilation and also a significant amount of pulmonary vasodilation. 24 refs., 7 figs., 2 tabs.

• OSTI ID: 5100842
• Journal Information: Journal of Applied Physiology (1985); (United States), Journal Name: Journal of Applied Physiology (1985); (United States) Vol. 75:3; ISSN JAPHEV; ISSN 8750-7587
• Country of Publication: United States
• Language: English

Related Subjects

560300* -- Chemicals Metabolism &amp; Toxicology
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BIOLOGICAL EFFECTS
BODY
CHALCOGENIDES
INHALATION
INTAKE
LUNGS
NITRIC OXIDE
NITROGEN COMPOUNDS
NITROGEN OXIDES
ORGANS
OXIDES
OXYGEN COMPOUNDS
RESPIRATORY SYSTEM
VASODILATION