Role of peptidoleukotrienes in hypoxic pulmonary vasoconstriction in rats

1990 ◽  
Vol 259 (3) ◽  
pp. H751-H758 ◽  
Author(s):  
T. J. McDonnell ◽  
J. Y. Westcott ◽  
J. Czartolomna ◽  
N. F. Voelkel
Keyword(s):  
Lung Tissue ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Lavage Fluid ◽  
Lung Lavage ◽  
Physiological Salt Solution ◽  
Slight Reduction ◽  
Lipoxygenase Inhibitor ◽  
Pulmonary Vasoconstriction ◽  
Eicosanoid Production

The role of leukotrienes in the mechanism of hypoxic pulmonary vasoconstriction (HPV) is controversial. To determine whether leukotriene C4 (LTC4) was produced during HPV, LTC4 levels were measured in individual samples of lung tissue, lung bronchoalveolar lavage fluid (BALF), and blood perfusate in isolated perfused lungs ventilated with normoxic or hypoxic gas mixtures. HPV was not associated with increased LTC4 in lung tissue or increased LTE4 in blood perfusate. Consistent with previous studies demonstrating elevated levels of LTC4 in pooled BALF fluid from hypoxic lungs, individual lung BALF samples demonstrated an elevation of LTC4 during hypoxia. However, the process of lung lavage alone stimulated eicosanoid production, with LTC4, 6-ketoprostaglandin F1 alpha, and thromboxane B2 levels being higher in lavaged compared to non-lavaged lungs. In lungs to which the lipoxygenase inhibitor AA 861 was added to the perfusate, a reduction in the lung tissue LTC4 levels was observed without any or only a slight reduction in HPV. To evaluate the physiological effects of LTC4 in the airways, exogenous LTC4 (1-1,000 ng) was added to the airways of both blood- and physiological salt solution-perfused lungs without any effect on the pulmonary artery pressure or a response to hypoxia. These results do not support the hypothesis that leukotrienes mediate HPV in the rat.

Mechanism of hypoxic pulmonary vasoconstriction involves ETA receptor-mediated inhibition of KATPchannel

2000 ◽  
Vol 278 (3) ◽  
pp. L434-L442 ◽  
Author(s):  
Koichi Sato ◽  
Yoshiteru Morio ◽  
Kenneth G. Morris ◽  
David M. Rodman ◽  
Ivan F. McMurtry
Keyword(s):  
Receptor Antagonist ◽  
Channel Blocker ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Physiological Salt Solution ◽  
Channel Activity ◽  
Pulmonary Vasoconstriction ◽  
Eta Receptor ◽  
Isolated Lungs ◽  
Subtype A

There is controversy on the role of endothelin (ET)-1 in the mechanism of hypoxic pulmonary vasoconstriction (HPV). Although HPV is inhibited by ET-1 subtype A (ETA)-receptor antagonists in animals, it has been reported that ETA-receptor blockade does not affect HPV in isolated lungs. Thus we reassessed the role of ET-1 in HPV in both rats and isolated blood- and physiological salt solution (PSS)-perfused rat lungs. In rats, the ETA-receptor antagonist BQ-123 and the nonselective ETA- and ETB-receptor antagonist PD-145065, but not the ETB-receptor antagonist BQ-788, inhibited HPV. Similarly, BQ-123, but not BQ-788, attenuated HPV in blood-perfused lungs. In PSS-perfused lungs, either BQ-123, BQ-788, or the combination of both attenuated HPV equally. Inhibition of HPV by combined BQ-123 and BQ-788 in PSS-perfused lungs was prevented by costimulation with angiotensin II. The ATP-sensitive K+(KATP)-channel blocker glibenclamide also prevented inhibition of HPV by BQ-123 in both lungs and rats. These results suggest that ET-1 contributes to HPV in both isolated lungs and intact animals through ETA receptor-mediated suppression of KATP-channel activity.

Role of eicosanoids in hypoxic vasoconstriction in isolated lamb lungs

1987 ◽  
Vol 253 (3) ◽  
pp. H626-H633 ◽  
Author(s):  
J. U. Raj ◽  
P. Chen
Keyword(s):  
Hypoxic Pulmonary Vasoconstriction ◽  
Pulmonary Arteries ◽  
Receptor Blocker ◽  
Lipoxygenase Inhibitor ◽  
Thromboxane Receptor ◽  
Thromboxane Synthetase ◽  
Vasoconstrictor Response ◽  
Micron Diameter ◽  
Arterial Constriction

To determine the role of eicosanoids in hypoxic pulmonary vasoconstriction, we studied 42 isolated, blood-perfused lamb lungs during normoxia and hypoxia. We used the lung micropuncture technique to measure microvascular pressures in 20- to 80-micron diameter arterioles and venules and estimated segmental vascular resistance. In separate experiments, lungs were untreated or treated with either indomethacin (a cyclooxygenase inhibitor), Dazmegrel (a thromboxane synthetase inhibitor), SQ 29548 (a thromboxane receptor blocker), FPL 57231 (a leukotriene receptor blocker), or U 60257 (a 5'lipoxygenase inhibitor). In control untreated lungs both pulmonary arteries and veins constricted during hypoxia. Addition of indomethacin, Dazmegrel, or SQ 29548 to the perfusate resulted in abolition of venous constriction during hypoxia but enhancement of arterial constriction. FPL 57231 or U 60257 resulted in complete abolition of the pulmonary hypoxic vasoconstrictor response. Our results indicate that during hypoxia, leukotrienes mediate arterial and venous constriction with thromboxane A2 being necessary for venous constriction. We conclude that the interaction between 5'lipoxygenase and cyclooxygenase products of arachidonic acid results in the characteristic pulmonary hypoxic vasoconstrictor response in isolated, perfused lamb lungs.

scholarly journals Role of ATP-sensitive potassium channels on hypoxic pulmonary vasoconstriction in endotoxemia

2018 ◽  
Vol 19 (1) ◽  
Author(s):  
Maurizio Turzo ◽  
Julian Vaith ◽  
Felix Lasitschka ◽  
Markus A. Weigand ◽  
Cornelius J. Busch
Keyword(s):  
Potassium Channels ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Pulmonary Vasoconstriction

Endothelium-derived relaxing factor activity in rat lung during hypoxic pulmonary vascular remodeling

1993 ◽  
Vol 74 (3) ◽  
pp. 1061-1065 ◽  
Author(s):  
L. Zhao ◽  
D. E. Crawley ◽  
J. M. Hughes ◽  
T. W. Evans ◽  
R. J. Winter
Keyword(s):  
Hypoxic Pulmonary Vasoconstriction ◽  
Hypoxic Exposure ◽  
Control Group ◽  
Pulmonary Vascular Remodeling ◽  
Relaxing Factor ◽  
Pulmonary Vasoconstriction ◽  
O2 Concentration ◽  
Pulmonary Arterial ◽  
Endothelium Derived Relaxing Factor

We have investigated the role of endothelium-derived relaxing factor in modulating hypoxic pulmonary vasoconstriction by inhibiting its synthesis with the false substrate NG-monomethyl-L-arginine (L-NMMA) in the isolated blood-perfused lungs of Wistar rats after chronic hypoxia (CH, fractional inspiratory O2 concentration 10%) for 15 h, 2 days, and 7 days. Lungs were perfused with blood of normal hematocrit at constant flow (18 ml/min) ventilated with 1) 95% air-5% CO2 (normoxia) and 2) 2% O2–5% CO2-93% N2 (hypoxia) and were studied in the absence and presence of L-NMMA (30 and 300 microM) or L-arginine (L-Arg, 1 and 6 mM) in separate groups. Pulmonary arterial pressure (Ppa) rose incrementally with hypoxic exposure (all P < 0.05 vs. normoxic control group). Hypoxic pulmonary vasoconstriction (HPV) was markedly reduced after 15 h and 2 days of CH: the mean increases in Ppa (delta Ppa) in hypoxia were 15.3, 3.5, 3.8, and 13.6 mmHg in control rats and rats exposed to 15 h (P < 0.05 vs. control and 7 days of CH), 2 days (P < 0.001 vs. control and 7 days of CH), and 7 days of CH, respectively. Ppa in control rats and rats exposed to 15 h, 2 days, and 7 days of CH were 137, 179, 184, and 166% of control, respectively, after 30 microM L-NMMA (all P < 0.05 when expressed as percent change vs. no L-NMMA). Similar augmentation in HPV was seen after 30 microM L-NMMA, with all hypoxic groups having a greater response than control groups.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Human neutrophil lipocalin (HNL) and myeloperoxidase (MPO). Studies of lung lavage fluid and lung tissue

2000 ◽  
Vol 94 (6) ◽  
pp. 564-568 ◽  
Author(s):  
B. SCHMEKEL ◽  
L. SEVEUS ◽  
S.Y. XU ◽  
P. VENGE
Keyword(s):  
Lung Tissue ◽  
Human Neutrophil ◽  
Lavage Fluid ◽  
Lung Lavage

scholarly journals Evidence for a role of protein kinase C in hypoxic pulmonary vasoconstriction

1999 ◽  
Vol 276 (1) ◽  
pp. L90-L95 ◽  
Author(s):  
Norbert Weissmann ◽  
Robert Voswinckel ◽  
Thorsten Hardebusch ◽  
Simone Rosseau ◽  
Hossein Ardeschir Ghofrani ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Nadph Oxidase ◽  
Superoxide Anion ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Ang Ii ◽  
Pkc Inhibitor ◽  
Pulmonary Vasoconstriction ◽  
Pressor Responses ◽  
Hypoxic Vasoconstriction

Hypoxic pulmonary vasoconstriction (HPV) matches lung perfusion to ventilation, thus optimizing gas exchange. NADPH oxidase-related superoxide anion generation has been suggested as part of the signaling response to hypoxia. Because protein kinase (PK) C activation can occur during hypoxia and PKC activation is known to be critical for NADPH oxidase stimulation in different cell types, we probed the role of PKC in hypoxic vasoconstriction in intact rabbit lungs. Control vasoconstrictor responses were elicited by angiotensin II (ANG II) and the stable thromboxane analog U-46619. Portions of the experiments were performed while NO synthesis and prostanoid generation were blocked with N G-monomethyl-l-arginine and acetylsalicylic acid to avoid confounding effects due to interference with these vasoactive mediators. The PKC inhibitor H-7 (10–50 μM) caused dose-dependent inhibition of HPV, but this agent lacked specificity because ANG II- and U-46619-induced vasoconstrictions were correspondingly suppressed. In contrast, low concentrations of the specific PKC inhibitor bisindolylmaleimide I (BIM; 1–15 μM) strongly inhibited the hypoxic vasoconstriction without any interference with the responses to the pharmacological agents. Superimposable dose-inhibition curves were also obtained for BIM when lung NO synthesis and prostanoid generation were blocked throughout the experiments. Under either condition, BIM did not affect normoxic vascular tone. The PKC activator farnesylthiotriazole (FTT), ascertained to stimulate rabbit NADPH oxidase by provocation of alveolar macrophage superoxide anion generation in vitro, caused rapid-onset, transient pressor responses in normoxic lungs. After FTT, the hypoxic vasoconstrictor response was totally suppressed, in contrast to the largely maintained pressor responses to ANG II and U-46619. The lungs became refractory even to delayed hypoxic challenges after FTT application. In conclusion, these data support the concept that activation of PKC is involved in the transduction pathway forwarding pulmonary vasoconstriction in response to alveolar hypoxia.

scholarly journals Effects of CX3CL1 inhibition on murine bleomycin-induced interstitial pneumonia

2020 ◽  
Vol 18 ◽  
pp. 205873922095990
Author(s):  
Soichi Yamada ◽  
Shion Miyoshi ◽  
Junko Nishio ◽  
Satoshi Mizutani ◽  
Zento Yamada ◽  
...  
Keyword(s):  
Interstitial Pneumonia ◽  
T Cell Activation ◽  
Lung Tissue ◽  
Cell Activation ◽  
Immunohistochemical Analysis ◽  
Inflammatory Cells ◽  
Lavage Fluid ◽  
Novel Therapy ◽  
Tissue Sections

Background: Treatment for interstitial pneumonia (IP) associated with collagen diseases has not been established. There is a need to elucidate the pathogenesis of IP and develop a novel therapy. We aimed to clarify the role of chemokine (C-X3-C motif) ligand 1 (CX3CL1, also known as fractalkine) in IP. Methods: Bleomycin (BLM) was intratracheally administered to C57BL/6 mice to induce IP. For treatment with control Ab or anti-CX3CL1 mAb, the mice were administered either Ab three times per week for 2 weeks from the day of BLM administration until euthanasia. Expressions of CX3CL1 and its unique receptor CX3CR1 in the lung tissue were examined by immunohistochemical analysis. Cellular infiltration and lung fibrosis were evaluated based on hematoxylin-eosin-staining and Sirius red staining of the lung tissue sections, respectively. Bronchoalveolar lavage fluid (BALF) cells were analyzed by flow cytometry. Results: CX3CL1 and CX3CR1 were strongly expressed in the lung tissue from mice with BLM-induced IP (BLM-IP). Treatment with anti-CX3CL1 mAb did not significantly alter inflammatory cell infiltration or fibrosis in the lung tissue. However, the number of M1-like macrophages in BALF was decreased and surface CD3 expression on T cells was increased by anti-CX3CL1 mAb treatment. Conclusions: Inhibition of CX3CL1 decreased inflammatory cells and may attenuate T cell activation in BALF. CX3CL1 inhibitor may have the potential to suppress the infiltration and activation of immune cells in IP.

Does leukotriene C4 mediate hypoxic vasoconstriction in isolated ferret lungs?

1990 ◽  
Vol 68 (1) ◽  
pp. 253-259 ◽  
Author(s):  
C. M. Tseng ◽  
M. McGeady ◽  
T. Privett ◽  
A. Dunn ◽  
J. T. Sylvester
Keyword(s):  
Pulmonary Arterial Pressure ◽  
Pressor Response ◽  
Hypoxic Pulmonary Vasoconstriction ◽  
Physiological Salt Solution ◽  
Leukotriene C4 ◽  
Prostaglandin F2 Alpha ◽  
Pulmonary Vasoconstriction ◽  
Vasoconstrictor Response ◽  
Hypoxic Vasoconstriction ◽  
Pulmonary Arterial

To evaluate leukotriene (LT) C4 as a mediator of hypoxic pulmonary vasoconstriction, we examined the effects of FPL55712, a putative LT antagonist, and indomethacin, a cyclooxygenase inhibitor, on vasopressor responses to LTC4 and hypoxia (inspired O2 tension = 25 Torr) in isolated ferret lungs perfused with a constant flow (50 ml.kg-1.min-1). Pulmonary arterial injections of LTC4 caused dose-related increases in pulmonary arterial pressure during perfusion with physiological salt solution containing Ficoll (4 g/dl). FPL55712 caused concentration-related inhibition of the pressor response to LTC4 (0.6 micrograms). Although 10 micrograms/ml FPL55712 inhibited the LTC4 pressor response by 61%, it did not alter the response to hypoxia. At 100 microgram/ml, FPL55712 inhibited the responses to LTC4 and hypoxia by 73 and 71%, respectively, but also attenuated the vasoconstrictor responses to prostaglandin F2 alpha (78% at 8 micrograms), phenylephrine (68% at 100 micrograms), and KCl (51% at 40 mM). At 0.5 microgram/ml, indomethacin significantly attenuated the pressor response to arachidonic acid but did not alter responses to LTC4 or hypoxia. These results suggest that in isolated ferret lungs 1) the vasoconstrictor response to LTC4 did not depend on release of cyclooxygenase products and 2) LTC4 did not mediate hypoxic vasoconstriction.

Sign in / Sign up

Export Citation Format

Share Document