scholarly journals Pulmonary hypertension triggered by lipopolysaccharide in ascites-susceptible and -resistant broilers is not amplified by aminoguanidine, a specific inhibitor of inducible nitric oxide synthase

2006 ◽  
Vol 85 (3) ◽  
pp. 528-536 ◽  
Author(s):  
O.T. Bowen ◽  
G.F. Erf ◽  
N.B. Anthony ◽  
R.F. Wideman
2001 ◽  
Vol 280 (2) ◽  
pp. L326-L333 ◽  
Author(s):  
Steven R. Kleeberger ◽  
Sekhar P. M. Reddy ◽  
Liu-Yi Zhang ◽  
Hye-Youn Cho ◽  
Anne E. Jedlicka

We tested the hypotheses that 1) inducible nitric oxide synthase (iNOS) mediates ozone (O3)-induced lung hyperpermeability and 2) mRNA levels of the gene for iNOS ( Nos2) are modulated by Toll-like receptor 4 ( Tlr4) during O3exposure. Pretreatment of O3-susceptible C57BL/6J mice with a specific inhibitor of total NOS ( NG-monomethyl-l-arginine) significantly decreased the mean lavageable protein concentration (a marker of lung permeability) induced by O3(0.3 parts/million for 72 h) compared with vehicle control mice. Furthermore, lavageable protein in C57BL/B6 mice with targeted disruption of Nos2 [ Nos2(−/−)] was 50% less than the protein in wild-type [ Nos2(+/+)] mice after O3. To determine whether Tlr4 modulates Nos2 mRNA levels, we studied C3H/HeJ (HeJ) and C3H/HeOuJ mice that differ only at a missense mutation in Tlr4 that confers resistance to O3-induced lung hyperpermeability in the HeJ strain. Nos2 and Tlr4 mRNA levels were significantly reduced and correlated in resistant HeJ mice after O3relative to those in susceptible C3H/HeOuJ mice. Together, the results are consistent with an important role for iNOS in O3-induced lung hyperpermeability and suggest that Nos2 mRNA levels are mediated through Tlr4.


Lung ◽  
2007 ◽  
Vol 185 (5) ◽  
pp. 303-308 ◽  
Author(s):  
Bao Hua Jiang ◽  
Junko Maruyama ◽  
Ayumu Yokochi ◽  
Yoshihide Mitani ◽  
Kazuo Maruyama

2021 ◽  
pp. 2101153
Author(s):  
Marija Gredic ◽  
Cheng-Yu Wu ◽  
Stefan Hadzic ◽  
Oleg Pak ◽  
Rajkumar Savai ◽  
...  

Pulmonary hypertension (PH) is a common complication of chronic obstructive pulmonary disease (COPD), associated with increased mortality and morbidity. Intriguingly, pulmonary vascular alterations have been suggested to drive emphysema development. We previously identified inducible nitric oxide synthase (iNOS) as an essential enzyme for development and reversal of smoke-induced PH and emphysema, and showed that iNOS expression in bone-marrow-derived cells drives pulmonary vascular remodelling, but not parenchymal destruction. In this study, we aimed to identify the iNOS-expressing cell type driving smoke-induced PH and to decipher pro-proliferative pathways involved.To address this question we used 1) myeloid cell-specific iNOS knockout mice in chronic smoke exposure, 2) co-cultures of macrophages and pulmonary artery smooth muscle cells (PASMC) to decipher underlying signalling pathways.Myeloid cell-specific iNOS knockout prevented smoke-induced PH but not emphysema in mice. Moreover, iNOS deletion in myeloid cells ameliorated the increase in expression of CD206, a marker of M2 polarisation, on interstitial macrophages. Importantly, the observed effects on lung macrophages were hypoxia-independent, as these mice developed hypoxia-induced PH. In vitro, smoke-induced PASMC proliferation in co-cultures with M2-polarised macrophages could be abolished by iNOS deletion in phagocytic cells, as well as by ERK inhibition in PASMC. Crucially, CD206-positive and iNOS-positive macrophages accumulated in proximity of remodelled vessels in the lungs of COPD patients, as shown by immunohistochemistry.In summary, our results demonstrate that iNOS deletion in myeloid cells confers protection against PH in smoke-exposed mice and provide evidence for an iNOS-dependent communication between M2-like macrophages and PASMC in underlying pulmonary vascular remodelling.


2006 ◽  
Vol 175 (4S) ◽  
pp. 96-96
Author(s):  
Masayoshi Nomura ◽  
Hisae Nishii ◽  
Masato Tsutsui ◽  
Naohiro Fujimoto ◽  
Tetsuro Matsumoto

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