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NG-monomethyl-L-arginine does not restore loss of hypoxic pulmonary vasoconstriction induced by TNF-alpha
- Source :
- Journal of Applied Physiology. 75:618-625
- Publication Year :
- 1993
- Publisher :
- American Physiological Society, 1993.
-
Abstract
- Tumor necrosis factor-alpha (TNF-alpha) causes systemic hypotension, pulmonary vasodilation, and loss of hypoxic pulmonary vasoconstriction. NG-monomethyl-L-arginine (L-NMMA) inhibits nitric oxide (NO) production and prevents some systemic manifestations of TNF-alpha. We tested using an isolated perfused canine lobe whether NO also mediates the pulmonary vascular effects of TNF-alpha. Total resistance (RT) was measured during control and hypoxic ventilation over a 90-min period in six control lobes, five lobes treated with TNF-alpha (250 micrograms), six lobes treated with L-NMMA (200 mg), and five lobes treated with L-NMMA (200 mg) + TNF-alpha (250 micrograms). In the control lobes RT increased (P < 0.02) from 0.0474 +/- 0.0105 to 0.0677 +/- 0.0133 cmH2O.ml-1 x min during normoxic and hypoxic ventilation, respectively. RT decreased (P < 0.05) from a baseline of 0.0593 +/- 0.0133 to 0.0449 +/- 0.0176 cmH2O.ml-1 x min 30 min after TNF-alpha administration and did not further change during hypoxic ventilation (0.0475 +/- 0.0107 cmH2O.ml-1 x min). L-NMMA pretreatment did not prevent the TNF-alpha-induced loss of hypoxic pulmonary vasoconstriction, with values of RT unchanged from normoxic (0.0541 +/- 0.0067 cmH2O.ml-1 x min) to hypoxic (0.0545 +/- 0.0078 cmH2O.ml-1.min) ventilation (P > 0.10) in the L-NMMA + TNF-alpha group after TNF-alpha administration. We conclude that NO is not the mediator responsible for the acute pulmonary vascular effects of TNF-alpha.
- Subjects :
- Pulmonary Circulation
medicine.medical_specialty
Arginine
Physiology
Blood Pressure
Nitric Oxide
Nitric oxide
chemistry.chemical_compound
Dogs
Physiology (medical)
Internal medicine
Hypoxic pulmonary vasoconstriction
medicine
Animals
Pulmonary Wedge Pressure
Hypoxia
omega-N-Methylarginine
Tumor Necrosis Factor-alpha
business.industry
Endothelium-derived relaxing factor
Hypoxia (medical)
Epoprostenol
Respiration, Artificial
Blood Cell Count
Perfusion
medicine.anatomical_structure
Endocrinology
chemistry
Vasoconstriction
Circulatory system
Vascular Resistance
Blood Gas Analysis
medicine.symptom
business
Filtration
Granulocytes
Blood vessel
Subjects
Details
- ISSN :
- 15221601 and 87507587
- Volume :
- 75
- Database :
- OpenAIRE
- Journal :
- Journal of Applied Physiology
- Accession number :
- edsair.doi.dedup.....481f7967787b762ad797c4341e74b08d