Site of pulmonary vasodilation by inhaled nitric oxide in the perfused lung

Journal Article · Mon May 01 04:00:00 EDT 1995 · Journal of Applied Physiology

OSTI ID:283155

Rimar, S; Gillis, C N ^[1]

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1. Yale Univ. School of Medicine, New Haven, CT (United States)

Site of pulmonary vasodilation by inhaled nitric oxide in the perfused lung. To determine the site of inhaled nitric oxide (NO)-induced pulmonary vasodilation, a double vascular occlusion technique was used with rabbit lungs ventilated and perfused at 20 ml/min with Krebs solution containing 3% dextran and 30 {mu}M indomethacin. Inhaled NO (120 ppm for 3% min) reduced pulmonary vasoconstriction produced by U-46619 infusion (0.5 -1.2 nmol/min), significantly decreasing total resistance (RT) [1,080 {plus_minus} 51 (SE) vs. 1,545 {plus_minus} 109 mmHg-min/l; P < 0.01]. Acetylcholine infusion (ACh; 2-5 nmol/min) and nitroglycerin (NTG; 0.35 {mu}mol) likewise decreased RT. Arterial resistance (Ra) was also significantly less with inhaled NO, ACh, and NTG compared with U-46619 alone. Venous resistance (Rv), however, was unchanged. When the direction of perfusion was reversed in the lung, inhaled NO, ACh, and NTG significantly decreased RT compared with U-46619 alone, and Rv was also reduced by all three agents. After electrolysis-induced acute lung injury, inhaled NO significantly reduced both RT and Ra compared with U-46619 alone, whereas Rv was unaffected. Our results demonstrate that inhaled NO gas affects primarily the arterial (precapillary) component of the pulmonary circulation but, under conditions of extreme venous constriction, may dilate the postcapillary component as well. 25 refs., 4 figs.

• OSTI ID: 283155
• Journal Information: Journal of Applied Physiology, Journal Name: Journal of Applied Physiology Journal Issue: 5 Vol. 78; ISSN JAPHEV; ISSN 8750-7587
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
INHALATION
LUNGS
NITRIC OXIDE
RABBITS
RESPIRATORY SYSTEM DISEASES
STATISTICS
THERAPY
VASODILATION