Congenital NOS2 deficiency prevents impairment of hypoxic pulmonary vasoconstriction in murine ventilator-induced lung injury

2007 ◽  
Vol 293 (5) ◽  
pp. L1300-L1305 ◽  
Author(s):  
Rong Liu ◽  
Yukako Hotta ◽  
Amanda R. Graveline ◽  
Oleg V. Evgenov ◽  
Emmanuel S. Buys ◽  
...  

Hypoxic pulmonary vasoconstriction (HPV) preserves systemic arterial oxygenation during lung injury by diverting blood flow away from poorly ventilated lung regions. Ventilator-induced lung injury (VILI) is characterized by pulmonary inflammation, lung edema, and impaired HPV leading to systemic hypoxemia. Studying mice congenitally deficient in inducible nitric oxide synthase (NOS2) and wild-type mice treated with a selective NOS2 inhibitor, l- N6-(1-iminoethyl)lysine (l-NIL), we investigated the contribution of NOS2 to the impairment of HPV in anesthetized mice subjected to 6 h of either high tidal volume (HVT) or low tidal volume (LVT) ventilation. HPV was estimated by measuring the changes of left lung pulmonary vascular resistance (LPVR) in response to left mainstem bronchus occlusion (LMBO). LMBO increased the LPVR similarly in wild-type, NOS2−/−, and wild-type mice treated with l-NIL 30 min before commencing 6 h of LVT ventilation (96% ± 30%, 103% ± 33%, and 80% ± 16%, respectively, means ± SD). HPV was impaired in wild-type mice subjected to 6 h of HVT ventilation (23% ± 16%). In contrast, HPV was preserved after 6 h of HVT ventilation in NOS2−/− and wild-type mice treated with l-NIL either 30 min before or 6 h after commencing HVT ventilation (66% ± 22%, 82% ± 29%, and 85% ± 16%, respectively). After 6 h of HVT ventilation and LMBO, systemic arterial oxygen tension was higher in NOS2−/− than in wild-type mice (192 ± 11 vs. 171 ± 17 mmHg; P < 0.05). We conclude that either congenital NOS2 deficiency or selective inhibition of NOS2 protects mice from the impairment of HPV occurring after 6 h of HVT ventilation.

2005 ◽  
Vol 103 (5) ◽  
pp. 996-1005 ◽  
Author(s):  
Waheedullah Karzai ◽  
Xizhong Cui ◽  
Norbert Heinicke ◽  
Christian Niemann ◽  
Eric P. Gerstenberger ◽  
...  

Background Based on the association between the neutrophil and ventilator-induced lung injury, the authors hypothesized that neutrophil inhibition with fucoidin would be beneficial and stimulation with granulocyte colony-stimulating factor (G-CSF) would be harmful in a rat model of lethal ventilator-induced lung injury. Methods Animals (n = 111) were randomly assigned to be pretreated with fucoidin, G-CSF, or placebo (control) before 4 h of low-tidal-volume (10 ml/kg) or high-tidal-volume (40 ml/kg) mechanical ventilation. Results All low-volume animals survived. With high volumes, compared with controls, fucoidin did not improve survival (3 of 20 control animals and 5 of 20 fucoidin animals died; P = 0.51) but G-CSF significantly worsened it (18 of 22 animals died; P &lt; 0.001). Circulating neutrophils were increased early with G-CSF and late with fucoidin with low and high tidal volumes (P &lt; 0.05 for each treatment and tidal volume). Fucoidin decreased lung neutrophils, but these were only significant with high tidal volumes, whereas G-CSF increased lung neutrophils but only significantly with low tidal volumes (P &lt; or = 0.01 for each). Fucoidin did not alter any cardiopulmonary measure significantly. Compared with control, G-CSF increased airway pressures with high tidal volumes and worsened lung edema and arterial oxygen with both tidal volumes (P &lt; 0.05 for each). Conclusions In this model, neutrophil stimulation by G-CSF increased lung dysfunction and with high tidal volumes worsened survival rates. Extrapolated clinically, neutrophil stimulation either by agents such as G-CSF or conditions such as sepsis may aggravate ventilator-induced lung injury.


Antioxidants ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 925
Author(s):  
Aron B. Fisher ◽  
Chandra Dodia ◽  
Shampa Chatterjee

Ventilator induced lung injury (VILI) is a lung injury syndrome associated with mechanical ventilation, most frequently for treatment of Acute Lung Injury (ALI), and generally secondary to the use of greater than physiologic tidal volumes. To reproduce this syndrome experimentally, C57Bl/6 mice were intubated and ventilated with low (4 mL/Kg body weight) or high (12 mL/Kg) tidal volume for 6 h. Lung parameters with low volume ventilation were unchanged from non-ventilated (control) mice. High tidal volume ventilation resulted in marked lung injury with increased neutrophils in the bronchoalveolar lavage fluid (BALF) indicating lung inflammation, increase in both protein in BALF and lung dry/wet weight indicating lung edema, increased lung thiobarbituric acid reactive substances (TBARS), and 8-isoprostanes indicating lung lipid peroxidation, and increased lung protein carbonyls indicating protein oxidation. Either intratracheal or intravenous pretreatment of mice with a 9 amino acid peptide called peroxiredoxin 6 inhibitor peptide-2 (PIP-2) significantly reduced all parameters of lung injury by ~50–80%. PIP-2 inhibits NADPH oxidase type 2 (NOX2) activation. We propose that PIP-2 does not affect the mechanically induced lung damage component of VILI but does significantly reduce the secondary inflammatory component.


2005 ◽  
Vol 98 (2) ◽  
pp. 748-752 ◽  
Author(s):  
Rong Liu ◽  
Oleg V. Evgenov ◽  
Fumito Ichinose

Nitric oxide (NO), synthesized by NO synthases (NOS), plays a pivotal role in regulation of pulmonary vascular tone. To examine the role of endothelial NOS (NOS3) in hypoxic pulmonary vasoconstriction (HPV), we measured left lung pulmonary vascular resistance (LPVR), intrapulmonary shunting, and arterial Po2 (PaO2) before and during left mainstem bronchus occlusion (LMBO) in mice with and without a deletion of the gene encoding NOS3. The increase of LPVR induced by LMBO was greater in NOS3-deficient mice than in wild-type mice (151 ± 39% vs. 109 ± 36%, mean ± SD; P < 0.05). NOS3-deficient mice had a lower intrapulmonary shunt fraction than wild-type mice (17.1 ± 3.6% vs. 21.7 ± 2.4%, P < 0.05) during LMBO. Both real-time PaO2 monitoring with an intra-arterial probe and arterial blood-gas analysis during LMBO showed higher PaO2 in NOS3-deficient mice than in wild-type mice ( P < 0.05). Inhibition of all three NOS isoforms with Nω-nitro-l-arginine methyl ester (l-NAME) augmented the increase of LPVR induced by LMBO in wild-type mice (183 ± 67% in l-NAME treated vs. 109 ± 36% in saline treated, P < 0.01) but not in NOS3-deficient mice. Similarly, systemic oxygenation during one-lung ventilation was augmented by l-NAME in wild-type mice but not in NOS3-deficient mice. These findings indicate that NO derived from NOS3 modulates HPV in vivo and that inhibition of NOS3 improves systemic oxygenation during acute unilateral lung hypoxia.


2019 ◽  
Vol 316 (2) ◽  
pp. L391-L399 ◽  
Author(s):  
Grigorij Schleifer ◽  
Eizo Marutani ◽  
Michele Ferrari ◽  
Rohit Sharma ◽  
Owen Skinner ◽  
...  

Hypoxic pulmonary vasoconstriction (HPV) is a physiological vasomotor response that maintains systemic oxygenation by matching perfusion to ventilation during alveolar hypoxia. Although mitochondria appear to play an essential role in HPV, the impact of mitochondrial dysfunction on HPV remains incompletely defined. Mice lacking the mitochondrial complex I (CI) subunit Ndufs4 ( Ndufs4−/−) develop a fatal progressive encephalopathy and serve as a model for Leigh syndrome, the most common mitochondrial disease in children. Breathing normobaric 11% O2 prevents neurological disease and improves survival in Ndufs4−/− mice. In this study, we found that either genetic Ndufs4 deficiency or pharmacological inhibition of CI using piericidin A impaired the ability of left mainstem bronchus occlusion (LMBO) to induce HPV. In mice breathing air, the partial pressure of arterial oxygen during LMBO was lower in Ndufs4−/− and in piericidin A-treated Ndufs4+/+ mice than in respective controls. Impairment of HPV in Ndufs4−/− mice was not a result of nonspecific dysfunction of the pulmonary vascular contractile apparatus or pulmonary inflammation. In Ndufs4-deficient mice, 3 wk of breathing 11% O2 restored HPV in response to LMBO. When compared with Ndufs4−/− mice breathing air, chronic hypoxia improved systemic oxygenation during LMBO. The results of this study show that, when breathing air, mice with a congenital Ndufs4 deficiency or chemically inhibited CI function have impaired HPV. Our study raises the possibility that patients with inborn errors of mitochondrial function may also have defects in HPV.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Haifa Xia ◽  
Jingxu Wang ◽  
Shujun Sun ◽  
Fuquan Wang ◽  
Yiyi Yang ◽  
...  

As one of the basic treatment modalities in the intensive care unit (ICU), mechanical ventilation can cause or aggravate acute lung injury or ventilator-induced lung injury (VILI). Resolvin D1 (RvD1) is an endogenous polyunsaturated fatty acid derivative with strong anti-inflammatory action. In this study, we explored if RvD1 possesses a protective effect on VILI. Mice were ventilated with high tidal volume (40 mL/kg, HVT) for 4 h and were then intraperitoneally administered RvD1 at the beginning of high tidal volume ventilation and given GW9662 (a PPAR-γ antagonist) intraperitoneally 30 min before ventilation. RvD1 attenuated VILI, as evidenced by improved oxygenation and reduced histological injury, compared with HVT -induced lung injury. Similarly, it could ameliorate neutrophil accumulation and production of proinflammatory cytokines in lung tissue. In contrast, the protective effect of RvD1 on lung tissue could be reversed by GW9662. RvD1 mitigated VILI by activating peroxisome proliferator-activated receptor gamma (PPAR-γ) and inhibiting nuclear factor-kappa B (NF-κB) signaling pathways in mice. In conclusion, RvD1 could reduce the inflammatory response in VILI by activating PPAR-γ and inhibiting NF-κB signaling pathways.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yan Huang ◽  
Gang Wang ◽  
Zhan Zhou ◽  
Zhengshan Tang ◽  
Ningning Zhang ◽  
...  

The gasotransmitter H2S is involved in various physiological and pathophysiological processes. The aim of this study was to investigate the physiological functions of H2S in the lungs. In the model of mouse with genetic deficiency in a H2S natural synthesis enzyme cystathionine-γ-lyase (CSE), we found that arterial oxygen saturation (SaO2) was decreased compared with wild type mice. Hypoxyprobe test showed that mild hypoxia occurred in the tissues of heart, lungs and kidneys in Cse-/- mice. H2S donor GYY4137 treatment increased SaO2 and ameliorated hypoxia state in cardiac and renal tissues. Further, we revealed that lung blood perfusion and airway responsiveness were not linked to reduced SaO2 level. Lung injury was found in Cse-/- mice as evidenced by alveolar wall thickening, diffuse interstitial edema and leukocyte infiltration in pulmonary tissues. IL-8, IL-1β, and TNF-α levels were markedly increased and oxidative stress levels were also significantly higher with increased levels of the pro-oxidative biomarker, MDA, decreased levels of the anti-oxidative biomarkers, T-AOC and GSH/GSSG, and reduced superoxide dismutase (SOD) activity in lung tissues of Cse-/- mice compared with those of wild type mice. GYY4137 treatment ameliorated lung injury and suppressed inflammatory state and oxidative stress in lung tissues of Cse-/- mice. A decrease in SaO2 was found in normal mice under hypoxia. These mice displayed lung injury as evidenced by alveolar wall thickening, interstitial edema and leukocyte infiltration. Increased levels of inflammatory cytokines and oxidative stress were also found in lung tissues of the mice with hypoxia insult. GYY4137 treatment increased SaO2 and ameliorated lung injury, inflammation and oxidative stress. Our data indicate that endogenous H2S is an important factor in maintaining normal SaO2 by preventing oxidative stress and inflammation in the lungs.


1995 ◽  
Vol 79 (6) ◽  
pp. 1951-1957 ◽  
Author(s):  
S. Deem ◽  
M. J. Bishop ◽  
M. K. Alberts

To elucidate the effects of anemia on intrapulmonary shunt, we studied a model of left lung atelectasis in anesthetized rabbits. In 10 rabbits, isovolemic anemia was produced by sequential hemodilution. Seven control rabbits were followed over time, without hemodilution. Intrapulmonary shunt (Qs/QT) was measured by using blood gas analysis and by quantitation of the percentage of blood flow to the collapsed left lung (QLl/QT) using fluorescent microspheres. In control rabbits, Qs/QT and QLl/QT decreased over time, whereas arterial PO2 increased. In hemodiluted rabbits, there was a trend toward increased Qs/QT and QLl/QT. There were significant differences in the behavior of Qs/QT, QLl/QT, and arterial PO2 between control and hemodiluted rabbits. Hemodynamic parameters, including cardiac output and pulmonary artery pressure, were not different between groups. In a third group of rabbits with pharmacologically induced acidosis but no hemodilution, Qs/QT and QLl/QT decreased over time, and arterial PO2 increased. We conclude that acute isovolemic anemia has a deleterious effect on pulmonary gas exchange, possibly through attenuation of hypoxic pulmonary vasoconstriction.


2006 ◽  
Vol 291 (4) ◽  
pp. L580-L587 ◽  
Author(s):  
Je Hyeong Kim ◽  
Min Hyun Suk ◽  
Dae Wui Yoon ◽  
Seung Heon Lee ◽  
Gyu Young Hur ◽  
...  

Neutrophils are considered to play a central role in ventilator-induced lung injury (VILI). However, the pulmonary consequences of neutrophil accumulation have not been fully elucidated. Matrix metalloproteinase-9 (MMP-9) had been postulated to participate in neutrophil transmigration. The purpose of this study was to investigate the role of MMP-9 in the neutrophilic inflammation of VILI. Male Sprague-Dawley rats were divided into three groups: 1) low tidal volume (LVT), 7 ml/kg of tidal volume (VT); 2) high tidal volume (HVT), 30 ml/kg of VT; and 3) HVT with MMP inhibitor (HVT+MMPI). As a MMPI, CMT-3 was administered daily from 3 days before mechanical ventilation. Degree of VILI was assessed by wet-to-dry weight ratio and acute lung injury (ALI) scores. Neutrophilic inflammation was determined from the neutrophil count in the lung tissue and myeloperoxidase (MPO) activity in the bronchoalveolar lavage fluid (BALF). MMP-9 expression and activity were examined by immunohistochemical staining and gelatinase zymography, respectively. The wet-to-dry weight ratio, ALI score, neutrophil infiltration, and MPO activity were increased significantly in the HVT group. However, in the HVT+MMPI group, pretreatment with MMPI decreased significantly the degree of VILI, as well as neutrophil infiltration and MPO activity. These changes correlated significantly with MMP-9 immunoreactivity and MMP-9 activity. Most outcomes were significantly worse in the HVT+MMPI group compared with the LVT group. In conclusion, VILI mediated by neutrophilic inflammation is closely related to MMP-9 expression and activity. The inhibition of MMP-9 protects against the development of VILI through the downregulation of neutrophil-mediated inflammation.


2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Xue Lin ◽  
Ying-nan Ju ◽  
Wei Gao ◽  
Dong-mei Li ◽  
Chang-chun Guo

Ventilator-induced lung injury aggravates the existing lung injury. This study investigated the effect of desflurane on VILI in a rat model of acute respiratory distress syndrome. Forty-eight rats were randomized into a sham (S) group, control (C) group, lipopolysaccharide/ventilation (LV) group, lipopolysaccharide/ventilation/desflurane (LVD) group, or lipopolysaccharide/low ventilation with and without desflurane (LLV and LLVD) groups. Rats in the S group received anesthesia only. Rats in the LV and LVD groups received lipopolysaccharide and were ventilated with a high tidal volume. Rats in LLV and LLVD groups were treated as the LV and LVD groups and ventilated with a low tidal volume. PaO2/FiO2, lung wet-to-dry weight ratios, concentrations of inflammatory factors in serum and BALF, histopathologic analysis of lung tissue, and levels of nuclear factor- (NF-) κB protein in lung tissue were investigated. PaO2/FiO2 was significantly increased by desflurane. Total cell count, macrophages, and neutrophils in BALF and proinflammatory factors in BALF and serum were significantly decreased by desflurane, while IL-10 was increased. The histopathological changes and levels of NF-κB protein in lung tissue were decreased by desflurane. The results indicated that desflurane ameliorated VILI in a rat model of acute respiratory distress syndrome.


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