Effect of LY171883 on endotoxin-induced lung injury in pigs

1990 ◽  
Vol 69 (4) ◽  
pp. 1315-1322 ◽  
Author(s):  
N. C. Olson ◽  
K. T. Kruse-Elliott ◽  
L. Johnson
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Injury ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Ex Vivo ◽  
Plasma Concentrations ◽  
Calcium Ionophore ◽  
Leukotriene D4 ◽  
Prostaglandin F2 Alpha ◽  
Capillary Membrane

We evaluated the role of sulfidopeptide leukotrienes as mediators of endotoxin-induced respiratory failure in pigs. Escherichia coli endotoxin (055-B5) was infused intravenously into anesthetized 10- to 14-wk-old pigs at 5 micrograms/kg the 1st h followed by 2 micrograms.kg-1.h-1 for 3 h in the presence and absence of LY171883, a specific leukotriene D4 (LTD4)/LTE4 receptor antagonist. Endotoxin caused hemoconcentration, granulocytopenia, decreased cardiac index, systemic hypotension, pulmonary hypertension, increased pulmonary vascular resistance, bronchoconstriction, hypoxemia, increased permeability of the alveolar-capillary membrane, pulmonary edema, and increased plasma concentrations of thromboxane B2 (TxB2), prostaglandin F2 alpha (PGF2 alpha), and 6-keto-PGF1 alpha. LY171883 did not modify endotoxin-induced cardiopulmonary and hematologic abnormalities, except for a modest attenuation of pulmonary hypertension (at 1 h) and increased pulmonary vascular resistance (at 1-2 h). Ex vivo stimulation of whole blood with calcium ionophore caused large increases in plasma concentrations of TxB2, PGF2 alpha, and LTB4. These increases were not significantly modified in blood derived from pigs treated with LY171883, indicating no inhibition of cyclooxygenase or 5-lipoxygenase. We conclude that LTD4 and LTE4 are not important mediators of endotoxin-induced lung injury in anesthetized pigs, although they may contribute modestly to pulmonary vasoconstriction.

Therapeutic hypercapnia prevents bleomycin-induced pulmonary hypertension in neonatal rats by limiting macrophage-derived tumor necrosis factor-α

2012 ◽  
Vol 303 (1) ◽  
pp. L75-L87 ◽  
Author(s):  
A. Charlotte P. Sewing ◽  
Crystal Kantores ◽  
Julijana Ivanovska ◽  
Alvin H. Lee ◽  
Azhar Masood ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Tumor Necrosis Factor ◽  
Lung Injury ◽  
Right Ventricular ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Tumor Necrosis ◽  
Neonatal Rat ◽  
Tnf Α ◽  
Necrosis Factor

Bleomycin-induced lung injury is characterized in the neonatal rat by inflammation, arrested lung growth, and pulmonary hypertension (PHT), as observed in human infants with severe bronchopulmonary dysplasia. Inhalation of CO2 (therapeutic hypercapnia) has been described to limit cytokine production and to have anti-inflammatory effects on the injured lung; we therefore hypothesized that therapeutic hypercapnia would prevent bleomycin-induced lung injury. Spontaneously breathing rat pups were treated with bleomycin (1 mg/kg/d ip) or saline vehicle from postnatal days 1–14 while being continuously exposed to 5% CO2 (PaCO2 elevated by 15–20 mmHg), 7% CO2 (PaCO2 elevated by 35 mmHg), or normocapnia. Bleomycin-treated animals exposed to 7%, but not 5%, CO2, had significantly attenuated lung tissue macrophage influx and PHT, as evidenced by normalized pulmonary vascular resistance and right ventricular systolic function, decreased right ventricular hypertrophy, and attenuated remodeling of pulmonary resistance arteries. The level of CO2 neither prevented increased tissue neutrophil influx nor led to improvements in decreased lung weight, septal thinning, impaired alveolarization, or decreased numbers of peripheral arteries. Bleomycin led to increased expression and content of lung tumor necrosis factor (TNF)-α, which was found to colocalize with tissue macrophages and to be attenuated by exposure to 7% CO2. Inhibition of TNF-α signaling with the soluble TNF-2 receptor etanercept (0.4 mg/kg ip from days 1–14 on alternate days) prevented bleomycin-induced PHT without decreasing tissue macrophages and, similar to CO2, had no effect on arrested alveolar development. Our findings are consistent with a preventive effect of therapeutic hypercapnia with 7% CO2 on bleomycin-induced PHT via attenuation of macrophage-derived TNF-α. Neither tissue macrophages nor TNF-α appeared to contribute to arrested lung development induced by bleomycin. That 7% CO2 normalized pulmonary vascular resistance and right ventricular function without improving inhibited airway and vascular development suggests that vascular hypoplasia does not contribute significantly to functional changes of PHT in this model.

Role of platelet-activating factor and eicosanoids during endotoxin-induced lung injury in pigs

1990 ◽  
Vol 258 (6) ◽  
pp. H1674-H1686 ◽  
Author(s):  
N. C. Olson ◽  
P. B. Joyce ◽  
L. N. Fleisher
Keyword(s):  
Lung Injury ◽  
Phase I ◽  
Receptor Antagonist ◽  
Ex Vivo ◽  
Plasma Concentrations ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Paf Receptor ◽  
Paf Receptor Antagonist

We hypothesized that platelet-activating factor (PAF) and eicosanoids might be important mediators of endotoxin-induced respiratory failure in pigs. Escherichia coli endotoxin (055-B5) was infused intravenously into anesthetized 10- to 14-wk-old pigs at 5 micrograms/kg the 1st h, followed by 2 micrograms.kg-1.h-1 for 3 h in the presence and absence of SRI 63-675, a specific PAF receptor antagonist. During phase I (i.e., 0-2 h), endotoxin caused pulmonary hypertension and hypoxemia, decreased cardiac index, increased pulmonary vascular resistance, and increased plasma concentrations of thromboxane B2 (TxB2), prostaglandin (PG)F2 alpha, and 6-keto-PGF1 alpha. These phase I effects were attenuated or blocked by SRI 63-675 (10 mg/kg before endotoxin + 3 mg.kg-1.h-1 during endotoxemia). During phase II endotoxemia (i.e., 2-4 h), the PAF receptor antagonist blocked endotoxin-induced pulmonary edema and hypoxemia and increased relative permeability index of the alveolar-capillary membrane. SRI 63-675 also blocked the endotoxin-induced increases in plasma and bronchoalveolar lavage fluid concentrations of leukotriene B4 (LTB4). Ex vivo stimulation of whole blood with calcium ionophore caused large increases in plasma concentrations of TxB2 and LTB4. These increases were not significantly modified in blood derived from pigs treated with SRI 63-675, indicating no inhibition of cyclooxygenase or 5-lipoxygenase and suggesting that the in vivo effects were PAF receptor mediated. We conclude that PAF plays an important role in the release of eicosanoids during endotoxemia and in mediating, either directly or indirectly, endotoxin-induced lung injury in anesthetized pigs.

scholarly journals Sex Dimorphism in Pulmonary Hypertension: The Role of the Sex Chromosomes

Antioxidants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 779
Author(s):  
Daria S. Kostyunina ◽  
Paul McLoughlin
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Sex Chromosomes ◽  
Bone Morphogenetic Protein 2 ◽  
Sex Dimorphism ◽  
Pulmonary Arterial ◽  
The Impact

Pulmonary hypertension (PH) is a condition characterised by an abnormal elevation of pulmonary artery pressure caused by an increased pulmonary vascular resistance, frequently leading to right ventricular failure and reduced survival. Marked sexual dimorphism is observed in patients with pulmonary arterial hypertension, a form of pulmonary hypertension with a particularly severe clinical course. The incidence in females is 2–4 times greater than in males, although the disease is less severe in females. We review the contribution of the sex chromosomes to this sex dimorphism highlighting the impact of proteins, microRNAs and long non-coding RNAs encoded on the X and Y chromosomes. These genes are centrally involved in the cellular pathways that cause increased pulmonary vascular resistance including the production of reactive oxygen species, altered metabolism, apoptosis, inflammation, vasoconstriction and vascular remodelling. The interaction with genetic mutations on autosomal genes that cause heritable pulmonary arterial hypertension such as bone morphogenetic protein 2 (BMPR2) are examined. The mechanisms that can lead to differences in the expression of genes located on the X chromosomes between females and males are also reviewed. A better understanding of the mechanisms of sex dimorphism in this disease will contribute to the development of more effective therapies for both women and men.

scholarly journals Inhaled Nitric Oxide at Birth Reduces Pulmonary Vascular Resistance and Improves Oxygenation in Preterm Lambs

Children ◽  
2021 ◽  
Vol 8 (5) ◽  
pp. 378
Author(s):  
Satyan Lakshminrusimha ◽  
Sylvia F. Gugino ◽  
Krishnamurthy Sekar ◽  
Stephen Wedgwood ◽  
Carmon Koenigsknecht ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Pulmonary Hypertension ◽  
Pulmonary Vascular Resistance ◽  
Preterm Infants ◽  
Vascular Resistance ◽  
Inhaled Nitric Oxide ◽  
Persistent Pulmonary Hypertension ◽  
Inhaled No ◽  
Birth Preterm

Resuscitation with 21% O2 may not achieve target oxygenation in preterm infants and in neonates with persistent pulmonary hypertension of the newborn (PPHN). Inhaled nitric oxide (iNO) at birth can reduce pulmonary vascular resistance (PVR) and improve PaO2. We studied the effect of iNO on oxygenation and changes in PVR in preterm lambs with and without PPHN during resuscitation and stabilization at birth. Preterm lambs with and without PPHN (induced by antenatal ductal ligation) were delivered at 134 d gestation (term is 147–150 d). Lambs without PPHN were ventilated with 21% O2, titrated O2 to maintain target oxygenation or 21% O2 + iNO (20 ppm) at birth for 30 min. Preterm lambs with PPHN were ventilated with 50% O2, titrated O2 or 50% O2 + iNO. Resuscitation with 21% O2 in preterm lambs and 50%O2 in PPHN lambs did not achieve target oxygenation. Inhaled NO significantly decreased PVR in all lambs and increased PaO2 in preterm lambs ventilated with 21% O2 similar to that achieved by titrated O2 (41 ± 9% at 30 min). Inhaled NO increased PaO2 to 45 ± 13, 45 ± 20 and 76 ± 11 mmHg with 50% O2, titrated O2 up to 100% and 50% O2 + iNO, respectively, in PPHN lambs. We concluded that iNO at birth reduces PVR and FiO2 required to achieve target PaO2.

Riociguat for HF with Pulmonary Hypertension (PH): Post-hoc Analysis of LEPHT by Baseline Pulmonary Vascular Resistance (PVR) and Pulmonary Vascular Gradient (PVG)

2014 ◽  
Vol 20 (8) ◽  
pp. S9 ◽  
Author(s):  
Diana Bonderman ◽  
Stefano Ghio ◽  
Stephan B. Felix ◽  
Hossein-Ardeschir Ghofrani ◽  
Evangelos Michelakis ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Post Hoc Analysis ◽  
Post Hoc

scholarly journals Cinaciguat, a soluble guanylate cyclase activator, causes potent and sustained pulmonary vasodilation in the ovine fetus

2009 ◽  
Vol 297 (2) ◽  
pp. L318-L325 ◽  
Author(s):  
Marc Chester ◽  
Pierre Tourneux ◽  
Greg Seedorf ◽  
Theresa R. Grover ◽  
Jason Gien ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Pulmonary Vascular Resistance ◽  
Vascular Resistance ◽  
Guanylate Cyclase ◽  
Soluble Guanylate Cyclase ◽  
Left Pulmonary Artery ◽  
Flow Transducer ◽  
Pulmonary Vasodilation

Impaired nitric oxide-cGMP signaling contributes to severe pulmonary hypertension after birth, which may in part be due to decreased soluble guanylate cyclase (sGC) activity. Cinaciguat (BAY 58-2667) is a novel sGC activator that causes vasodilation, even in the presence of oxidized heme or heme-free sGC, but its hemodynamic effects have not been studied in the perinatal lung. We performed surgery on eight fetal (126 ± 2 days gestation) lambs (full term = 147 days) and placed catheters in the main pulmonary artery, aorta, and left atrium to measure pressures. An ultrasonic flow transducer was placed on the left pulmonary artery to measure blood flow, and a catheter was placed in the left pulmonary artery for drug infusion. Cinaciguat (0.1–100 μg over 10 min) caused dose-related increases in pulmonary blood flow greater than fourfold above baseline and reduced pulmonary vascular resistance by 80%. Treatment with 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), an sGC-oxidizing inhibitor, enhanced cinaciguat-induced pulmonary vasodilation by >120%. The pulmonary vasodilator effect of cinaciguat was prolonged, decreasing pulmonary vascular resistance for >1.5 h after brief infusion. In vitro stimulation of ovine fetal pulmonary artery smooth muscle cells with cinaciguat after ODQ treatment resulted in a 14-fold increase in cGMP compared with non-ODQ-treated cells. We conclude that cinaciguat causes potent and sustained fetal pulmonary vasodilation that is augmented in the presence of oxidized sGC and speculate that cinaciguat may have therapeutic potential for severe neonatal pulmonary hypertension.

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