TY - JOUR
T1 - Differential effects of nitrovasodilators and nitric oxide on porcine tracheal and bronchial muscle in vitro
AU - Stuart-Smith, K.
AU - Bynoe, T. C.
AU - Lindeman, K. S.
AU - Hirshman, C. A.
N1 - Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 1994
Y1 - 1994
N2 - Nitrovasodilators and nitric oxide relax airway smooth muscle. The mechanism by which nitrovasodilators are thought to act is by release of nitric oxide, but the importance of nitric oxide in nitrovasodilator-induced airway smooth muscle relaxation is unclear. The aim of this study was to compare the relaxing effects of nitric oxide itself with those of nitrovasodilators in porcine tracheal muscle and intrapulmonary airways and to investigate the mechanisms involved. Strips of porcine tracheal smooth muscle, rings of bronchi, and strips of bronchi from the same animal were suspended in organ chambers in modified Krebs Ringer solution (95% O2-5% CO2, 37°C). Tissues were contracted with carbachol, and concentration- response curves to nitric oxide, sodium nitroprusside, and SIN-1 (an active metabolite of molsidomine) were obtained. All tissues relaxed to sodium nitroprusside, SIN-1, and nitric oxide. The relaxation to nitric oxide but not to SIN-1 or sodium nitroprusside was inhibited by methylene blue. Tissues pretreated with methylene blue that failed to relax to nitric oxide were, however, relaxed by sodium nitroprusside. These results demonstrate that nitrovasodilators relax airways by a mechanism other than by or in addition to the release of nitric oxide.
AB - Nitrovasodilators and nitric oxide relax airway smooth muscle. The mechanism by which nitrovasodilators are thought to act is by release of nitric oxide, but the importance of nitric oxide in nitrovasodilator-induced airway smooth muscle relaxation is unclear. The aim of this study was to compare the relaxing effects of nitric oxide itself with those of nitrovasodilators in porcine tracheal muscle and intrapulmonary airways and to investigate the mechanisms involved. Strips of porcine tracheal smooth muscle, rings of bronchi, and strips of bronchi from the same animal were suspended in organ chambers in modified Krebs Ringer solution (95% O2-5% CO2, 37°C). Tissues were contracted with carbachol, and concentration- response curves to nitric oxide, sodium nitroprusside, and SIN-1 (an active metabolite of molsidomine) were obtained. All tissues relaxed to sodium nitroprusside, SIN-1, and nitric oxide. The relaxation to nitric oxide but not to SIN-1 or sodium nitroprusside was inhibited by methylene blue. Tissues pretreated with methylene blue that failed to relax to nitric oxide were, however, relaxed by sodium nitroprusside. These results demonstrate that nitrovasodilators relax airways by a mechanism other than by or in addition to the release of nitric oxide.
KW - SIN-1
KW - airway smooth muscle
KW - porcine airways
KW - sodium nitroprusside
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U2 - 10.1152/jappl.1994.77.3.1142
DO - 10.1152/jappl.1994.77.3.1142
M3 - Article
C2 - 7836115
AN - SCOPUS:0027941286
SN - 8750-7587
VL - 77
SP - 1142
EP - 1147
JO - Journal of applied physiology
JF - Journal of applied physiology
IS - 3
ER -