scholarly journals A New Century of Pharmacology Is Coming. Probable involvement of the augmented agonist-induced Ca2+ sensitization of airway smooth muscle contraction in the pathogenesis of airway hyperresponsiveness.

1999 ◽  
Vol 114 (3) ◽  
pp. 185-190 ◽  
Author(s):  
Yoshihiko CHIBA ◽  
Miwa MISAWA
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Smooth Muscle Contraction

scholarly journals ROCK insufficiency attenuates ozone-induced airway hyperresponsiveness in mice

2015 ◽  
Vol 309 (7) ◽  
pp. L736-L746 ◽  
Author(s):  
David I. Kasahara ◽  
Joel A. Mathews ◽  
Chan Y. Park ◽  
Youngji Cho ◽  
Gabrielle Hunt ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Matrix Protein ◽  
Pulmonary Inflammation ◽  
Inflammatory Cells ◽  
Smooth Muscle Contraction ◽  
Airway Smooth Muscle Cells ◽  
Wild Type

Ozone causes airway hyperresponsiveness (AHR) and pulmonary inflammation. Rho kinase (ROCK) is a key regulator of smooth muscle cell contraction and inflammatory cell migration. To determine the contribution of the two ROCK isoforms ROCK1 and ROCK2 to ozone-induced AHR, we exposed wild-type, ROCK1+/−, and ROCK2+/− mice to air or ozone (2 ppm for 3 h) and evaluated mice 24 h later. ROCK1 or ROCK2 haploinsufficiency did not affect airway responsiveness in air-exposed mice but significantly reduced ozone-induced AHR, with a greater reduction in ROCK2+/− mice despite increased bronchoalveolar lavage (BAL) inflammatory cells in ROCK2+/− mice. Compared with wild-type mice, ozone-induced increases in BAL hyaluronan, a matrix protein implicated in ozone-induced AHR, were lower in ROCK1+/− but not ROCK2+/− mice. Ozone-induced increases in other inflammatory moieties reported to contribute to ozone-induced AHR (IL-17A, osteopontin, TNFα) were not different in wild-type vs. ROCK1+/− or ROCK2+/− mice. We also observed a dose-dependent reduction in ozone-induced AHR after treatment with the ROCK1/ROCK2 inhibitor fasudil, even though fasudil was administered after induction of inflammation. Ozone increased pulmonary expression of ROCK2 but not ROCK1 or RhoA. A ROCK2 inhibitor, SR3677, reduced contractile forces in primary human airway smooth muscle cells, confirming a role for ROCK2 in airway smooth muscle contraction. Our results demonstrate that ozone-induced AHR requires ROCK. Whereas ROCK1-dependent changes in hyaluronan may contribute to ROCK1's role in O3-induced AHR, the role of ROCK2 is downstream of inflammation, likely at the level of airway smooth muscle contraction.

Intrinsic and antigen-induced airway hyperresponsiveness are the result of diverse physiological mechanisms

2007 ◽  
Vol 102 (1) ◽  
pp. 221-230 ◽  
Author(s):  
Scott S. Wagers ◽  
Hans C. Haverkamp ◽  
Jason H. T. Bates ◽  
Ryan J. Norton ◽  
John A. Thompson-Figueroa ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Smooth Muscle Contraction ◽  
Airway Closure ◽  
Physiological Mechanisms ◽  
Airway Constriction ◽  
Normal Airway ◽  
Central Airway

Airway hyperresponsiveness (AHR) is a defining feature of asthma. We have previously shown, in mice sensitized and challenged with antigen, that AHR is attributable to normal airway smooth muscle contraction with exaggerated airway closure. In the present study we sought to determine if the same was true for mice known to have intrinsic AHR, the genetic strain of mice, A/J. We found that A/J mice have AHR characterized by minimal increase in elastance following aerosolized methacholine challenge compared with mice (BALB/c) that have been antigen sensitized and challenged [concentration that evokes 50% change in elastance (PC50): 22.9 ± 5.7 mg/ml for A/J vs. 3.3 ± 0.4 mg/ml for antigen-challenged and -sensitized mice; P < 0.004]. Similar results were found when intravenous methacholine was used (PC30 0.22 ± 0.08 mg/ml for A/J vs. 0.03 ± 0.004 mg/ml for antigen-challenged and -sensitized mice). Computational model analysis revealed that the AHR in A/J mice is dominated by exaggerated airway smooth muscle contraction and that when the route of methacholine administration was changed to intravenous, central airway constriction dominates. Absorption atelectasis was used to provide evidence of the lack of airway closure in A/J mice. Bronchoconstriction during ventilation with 100% oxygen resulted in a mean 9.8% loss of visible lung area in A/J mice compared with 28% in antigen-sensitized and -challenged mice ( P < 0.02). We conclude that the physiology of AHR depends on the mouse model used and the route of bronchial agonist administration.

Ozone-induced airway hyperresponsiveness: roles of ROCK isoforms

2015 ◽  
Vol 309 (12) ◽  
pp. L1394-L1397 ◽  
Author(s):  
James A. Lambert ◽  
Weifeng Song
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Airway Hyperresponsiveness ◽  
Rho Kinase ◽  
Smooth Muscle Contraction ◽  
Wild Type ◽  
Epithelial Injury ◽  
Robust Evidence

Acute ozone (O3) inhalation has been shown to cause airway and pulmonary epithelial injury with accompanying inflammation responses. Robust evidence exists that O3 induces airway hyperresponsiveness (AHR) in humans and in animal models. Several pathways exist that culminate in airway smooth muscle contraction, but the mechanism(s) by which O3 elicits AHR are unclear. Here, we review the recent report by Kasahara et al. (Kasahara DI, Mathews JA, Park CY, Cho Y, Hunt G, Wurmbrand AP, Liao JK, Shore SA. Am J Physiol Lung Cell Mol Physiol 309: L736–L746, 2015.) describing the role of two Rho kinase (ROCK) isoforms in O3-induced AHR utilizing a murine haploinsufficiency model. Compared with wild-type (WT) mice, the authors report that ROCK1+/− and ROCK2+/− mice exhibited significantly reduced AHR following acute exposure to O3. Additionally, WT mice treated with fasudil, an FDA-approved ROCK1/2 inhibitor, recapitulated reduction in AHR as seen in ROCK haplotypes. It was suggested that, although the two ROCK isoforms are both induced by Rho, they have different mechanisms by which they mediate O3-induced AHR: ROCK1 via hyaluronan signaling vs. ROCK2 acting downstream of inflammation at the level of airway smooth muscle contraction. These observations provide an important framework to develop novel ROCK-targeting therapies for acute O3-induced AHR.

Lower airway smooth muscle contraction induced by (red tide) toxin

1987 ◽  
Vol 79 (6) ◽  
pp. 899-908 ◽  
Author(s):  
T SHIMODA ◽  
J KRZANOWSKI ◽  
R LOCKEY ◽  
D MARTIN ◽  
M PEREZCRUET ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Red Tide ◽  
Smooth Muscle Contraction ◽  
Lower Airway

scholarly journals Allergic sensitization enhances the contribution of Rho-kinase to airway smooth muscle contraction

2004 ◽  
Vol 143 (4) ◽  
pp. 477-484 ◽  
Author(s):  
Dedmer Schaafsma ◽  
Reinoud Gosens ◽  
I Sophie T Bos ◽  
Herman Meurs ◽  
Johan Zaagsma ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Muscle Contraction ◽  
Airway Smooth Muscle ◽  
Allergic Sensitization ◽  
Rho Kinase ◽  
Smooth Muscle Contraction
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