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Fetal pulmonary hypertension: dysregulated microRNA-34c-Notch1 axis contributes to impaired angiogenesis in an ovine model. Pediatr Res 2023; 93:551-558. [PMID: 35717485 PMCID: PMC9759620 DOI: 10.1038/s41390-022-02151-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2021] [Revised: 05/17/2022] [Accepted: 05/26/2022] [Indexed: 11/09/2022]
Abstract
BACKGROUND Persistent pulmonary hypertension of the newborn (PPHN) occurs when pulmonary vascular resistance (PVR) fails to decrease at birth. Decreased angiogenesis in the lung contributes to the persistence of high PVR at birth. MicroRNAs (miRNAs) regulate gene expression through transcript binding and degradation. They were implicated in dysregulated angiogenesis in cancer and cardiovascular disease. METHODS We investigated whether altered miRNA levels contribute to impaired angiogenesis in PPHN. We used a fetal lamb model of PPHN induced by prenatal ductus arteriosus constriction and sham ligation as controls. We performed RNA sequencing of pulmonary artery endothelial cells (PAECs) isolated from control and PPHN lambs. RESULTS We observed a differentially expressed miRNA profile in PPHN for organ development, cell-cell signaling, and cardiovascular function. MiR-34c was upregulated in PPHN PAECs compared to controls. Exogenous miR34c mimics decreased angiogenesis by control PAEC and anti-miR34c improved angiogenesis of PPHN PAEC in vitro. Notch1, a predicted target for miR-34c by bioinformatics, was decreased in PPHN PAECs, along with Notch1 downstream targets, Hey1 and Hes1. Exogenous miR-34c decreased Notch1 expression in control PAECs and anti-miR-34c restored Notch1 and Hes1 expression in PPHN PAECs. CONCLUSION We conclude that increased miR-34c in PPHN contributes to impaired angiogenesis by decreasing Notch1 expression in PAECs. IMPACT Adds a novel mechanism for the regulation of angiogenesis in persistent pulmonary hypertension of the newborn. Identifies non-coding RNAs that are involved in the altered angiogenesis in PPHN and thus the potential for future studies to identify links between known pathways regulating angiogenesis. Provides preliminary data to conduct studies targeting miR34c expression in vivo in animal models of pulmonary hypertension to identify the mechanistic role of miR34c in angiogenesis in the lung vasculature.
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Daneva Z, Ottolini M, Chen YL, Klimentova E, Kuppusamy M, Shah SA, Minshall RD, Seye CI, Laubach VE, Isakson BE, Sonkusare SK. Endothelial pannexin 1-TRPV4 channel signaling lowers pulmonary arterial pressure in mice. eLife 2021; 10:67777. [PMID: 34490843 PMCID: PMC8448527 DOI: 10.7554/elife.67777] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 09/06/2021] [Indexed: 12/14/2022] Open
Abstract
Pannexin 1 (Panx1), an ATP-efflux pathway, has been linked with inflammation in pulmonary capillaries. However, the physiological roles of endothelial Panx1 in the pulmonary vasculature are unknown. Endothelial transient receptor potential vanilloid 4 (TRPV4) channels lower pulmonary artery (PA) contractility and exogenous ATP activates endothelial TRPV4 channels. We hypothesized that endothelial Panx1–ATP–TRPV4 channel signaling promotes vasodilation and lowers pulmonary arterial pressure (PAP). Endothelial, but not smooth muscle, knockout of Panx1 increased PA contractility and raised PAP in mice. Flow/shear stress increased ATP efflux through endothelial Panx1 in PAs. Panx1-effluxed extracellular ATP signaled through purinergic P2Y2 receptor (P2Y2R) to activate protein kinase Cα (PKCα), which in turn activated endothelial TRPV4 channels. Finally, caveolin-1 provided a signaling scaffold for endothelial Panx1, P2Y2R, PKCα, and TRPV4 channels in PAs, promoting their spatial proximity and enabling signaling interactions. These results indicate that endothelial Panx1–P2Y2R–TRPV4 channel signaling, facilitated by caveolin-1, reduces PA contractility and lowers PAP in mice.
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Affiliation(s)
- Zdravka Daneva
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States
| | - Matteo Ottolini
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States.,Department of Pharmacology, University of Virginia, Charlottesville, United States
| | - Yen Lin Chen
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States
| | - Eliska Klimentova
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States
| | - Maniselvan Kuppusamy
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States
| | - Soham A Shah
- Department of Biomedical Engineering, University of Virginia, Charlottesville, United States
| | - Richard D Minshall
- Department of Anesthesiology, Department of Pharmacology, University of Illinois, Chicago, United States
| | - Cheikh I Seye
- Department of Biochemistry, University of Missouri-Columbia, Columbia, United States
| | - Victor E Laubach
- Department of Surgery, University of Virginia, Charlottesville, United States
| | - Brant E Isakson
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
| | - Swapnil K Sonkusare
- Robert M. Berne Cardiovascular Research Center, University of Virginia, Charlottesville, United States.,Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, United States
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3
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Muller MA, Xie A, Qi Y, Zhao Y, Ozawa K, Noble-Vranish M, Lindner JR. Regional and Conducted Vascular Effects of Endovascular Ultrasound Catheters. ULTRASOUND IN MEDICINE & BIOLOGY 2020; 46:2361-2369. [PMID: 32522456 PMCID: PMC7720779 DOI: 10.1016/j.ultrasmedbio.2020.05.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 05/06/2020] [Accepted: 05/10/2020] [Indexed: 06/03/2023]
Abstract
Intra-vascular ultrasound catheters are used clinically to facilitate clot lysis. We hypothesized that these devices could also directly lower microvascular resistance and increase tissue perfusion through established shear-dependent pathways. In mice, either the proximal hind-limb muscles or the upstream femoral artery alone was exposed to an endovascular ultrasound catheter (2.3 MHz, 0.5-1.1 MPa) for 10 min. Quantitative microvascular perfusion imaging in the hind limbs exposed to the endovascular ultrasound system exhibited a more-than-twofold increase in flow (p < 0.01) compared with the contralateral control limb after exposure of either the muscle or the femoral artery alone. Using an in vivo optical imaging reporting system, an eight- to ninefold increase in tissue adenosine triphosphate (ATP) was detected in the region of insonification (p = 0.006). Ultrasound was found to produce an immediate release of ATP from ex vivo erythrocytes (p = 0.03). In situ electrochemical sensing revealed an immediate increase in nitric oxide with initiation of ultrasound which returned to baseline within 5 min of termination, as well as ultrasound-triggered nitric oxide (NO) release from erythrocytes. These data indicate that non-cavitating ultrasound produced by endovascular catheters can reduce vascular resistance and increase flow through recognized shear-dependent vasodilator pathways involving purinergic signaling and NO.
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Affiliation(s)
- Matthew A Muller
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Aris Xie
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Yue Qi
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Yan Zhao
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | - Koya Ozawa
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA
| | | | - Jonathan R Lindner
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA; Oregon National Primate Research Center, Oregon Health & Science University, Portland, Oregon, USA.
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Maternal Diabetes Mellitus and Persistent Pulmonary Hypertension of the Newborn: Accumulated Evidence From Observational Studies. Can J Diabetes 2020; 44:327-334.e3. [PMID: 31902718 DOI: 10.1016/j.jcjd.2019.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 10/08/2019] [Accepted: 10/08/2019] [Indexed: 01/12/2023]
Abstract
OBJECTIVES Maternal diabetes mellitus (including pre-existing and gestational diabetes mellitus) is linked with adverse infant outcomes. However, the question of whether maternal diabetes increases the risk of persistent pulmonary hypertension of the newborn (PPHN) is unclear. Herein, we conducted a systematic review and meta-analysis to summarize clinical evidence to determine the association between maternal diabetes mellitus and PPHN. METHODS In this systematic review and meta-analysis, we systematically searched PubMed, Embase, Cochrane Library, Web of Science and Google Scholar to identify relevant studies according to predefined criteria. Data from selected studies were extracted, and meta-analysis was performed using fixed effects modelling. RESULTS In all, we included 7 unique studies with aggregated data on 2 million individuals and >5,000 cases of PPHN. Maternal diabetes was significantly associated with a higher risk of PPHN (risk ratio [RR], 1.37; 95% confidence interval [CI], 1.23 to 1.51). Both case-control and cohort studies exhibited that the presence of maternal diabetes increased the risk of PPHN (case-control: RR, 1.91; 95% CI, 1.02 to 2.79; cohort: RR, 1.36; 95% CI, 1.22 to 1.50). By omitting 1 study at a time, sensitivity analysis made sure that no individual study was entirely responsible for the combined results. CONCLUSIONS Maternal diabetes was associated with increased risk of PPHN. For babies with refractory hypoxemia, with mothers with diabetes, PPHN should be taken into consideration in clinical practice.
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Metabolomics coupled with system pharmacology reveal the protective effect of total flavonoids of Astragali Radix against adriamycin-induced rat nephropathy model. J Pharm Biomed Anal 2018; 158:128-136. [DOI: 10.1016/j.jpba.2018.05.045] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 05/29/2018] [Accepted: 05/29/2018] [Indexed: 11/22/2022]
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6
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Ke X, Johnson H, Jing X, Michalkiewicz T, Huang YW, Lane RH, Konduri GG. Persistent pulmonary hypertension alters the epigenetic characteristics of endothelial nitric oxide synthase gene in pulmonary artery endothelial cells in a fetal lamb model. Physiol Genomics 2018; 50:828-836. [PMID: 30004838 DOI: 10.1152/physiolgenomics.00047.2018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Decreased expression of endothelial nitric oxide synthase (eNOS), a key mediator of perinatal transition, characterizes persistent pulmonary hypertension of the newborn (PPHN) in neonates and a fetal lamb model; the mechanisms are unclear. We investigated whether increased DNA CpG methylation at the eNOS promoter in estrogen response elements (EREs) and altered histone code together contribute to decreased eNOS expression in PPHN. We isolated pulmonary artery endothelial cells (PAEC) from fetal lambs with PPHN induced by prenatal ductus arteriosus constriction from 128 to 136 days gestation or gestation-matched twin controls. We measured right ventricular systolic pressure (RVSP) and Fulton index and determined eNOS expression in PAEC in control and PPHN lambs. We determined DNA CpG methylation by pyrosequencing and activity of ten eleven translocase demethylases (TET) by colorimetric assay. We quantified the occupancy of transcription factors, specificity protein 1 (Sp1), and estrogen receptors and density of four histone marks around Sp1 binding sites by chromatin immunoprecipitation (ChIP) assays. Fetal lambs with PPHN developed increased RVSP and Fulton index. Levels of eNOS mRNA and protein were decreased in PAEC from PPHN lambs. PPHN significantly increased the DNA CpG methylation in eNOS promoter and decreased TET activity in PAEC. PPHN decreased Sp1 occupancy and density of the active mark, lysine 12 acetylation of histone 4, and increased density of the repression mark, lysine 9 trimethylation of histone 3 around Sp1 binding sites in eNOS promoter. These results suggest that epigenetic modifications are primed to decrease Sp1 binding at the eNOS gene promoter in PPHN.
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Affiliation(s)
- Xingrao Ke
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Hollis Johnson
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Xigang Jing
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Teresa Michalkiewicz
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Yi-Wen Huang
- Department of Obstetrics and Gynecology, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Robert H Lane
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin , Milwaukee, Wisconsin
| | - Girija G Konduri
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin , Milwaukee, Wisconsin
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Henriquez M, Fonseca M, Perez-Zoghbi JF. Purinergic receptor stimulation induces calcium oscillations and smooth muscle contraction in small pulmonary veins. J Physiol 2018; 596:2491-2506. [PMID: 29790164 DOI: 10.1113/jp274731] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 04/11/2018] [Indexed: 01/05/2023] Open
Abstract
KEY POINTS We investigated the excitation-contraction coupling mechanisms in small pulmonary veins (SPVs) in rat precision-cut lung slices. We found that SPVs contract strongly and reversibly in response to extracellular ATP and other vasoconstrictors, including angiotensin-II and endothelin-1. ATP-induced vasoconstriction in SPVs was associated with the stimulation of purinergic P2Y2 receptors in vascular smooth muscle cell, activation of phospholipase C-β and the generation of intracellular Ca2+ oscillations mediated by cyclic Ca2+ release events via the inositol 1,4,5-trisphosphate receptor. Active constriction of SPVs may play an important role in the development of pulmonary hypertension and pulmonary oedema. ABSTRACT The small pulmonary veins (SPVs) may play a role in the development of pulmonary hypertension and pulmonary oedema via active changes in SPV diameter, mediated by vascular smooth muscle cell (VSMC) contraction. However, the excitation-contraction coupling mechanisms during vasoconstrictor stimulation remain poorly understood in these veins. We used rat precision-cut lung slices and phase-contrast and confocal microscopy to investigate dynamic changes in SPV cross-sectional luminal area and intracellular Ca2+ signalling in their VSMCs. We found that the SPV (∼150 μm in diameter) contract strongly in response to extracellular ATP and other vasoconstrictors, including angiotensin-II and endothelin-1. ATP-induced SPV contraction was fast, concentration-dependent, completely reversible upon ATP washout, and inhibited by purinergic receptor antagonists suramin and AR-C118925 but not by MRS2179. Immunofluorescence showed purinergic P2Y2 receptors expressed in SPV VSMCs. ATP-induced SPV contraction was inhibited by phospholipase Cβ inhibitor U73122 and accompanied by intracellular Ca2+ oscillations in the VSMCs. These Ca2+ oscillations and SPV contraction were inhibited by the inositol 1,4,5-trisphosphate receptor inhibitor 2-APB but not by ryanodine. The results of the present study suggest that ATP-induced vasoconstriction in SPVs is associated with the activation of purinergic P2Y2 receptors in VSMCs and the generation of Ca2+ oscillations.
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Affiliation(s)
- Mauricio Henriquez
- Program of Physiology and Biophysics, ICBM, Faculty of Medicine, University of Chile, Independencia 1027, Santiago, Chile
| | - Marcelo Fonseca
- Program of Physiology and Biophysics, ICBM, Faculty of Medicine, University of Chile, Independencia 1027, Santiago, Chile
| | - Jose F Perez-Zoghbi
- Department of Anesthesiology, College of Physicians & Surgeons, Columbia University Medical Center, New York, NY, USA
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8
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Marziano C, Hong K, Cope EL, Kotlikoff MI, Isakson BE, Sonkusare SK. Nitric Oxide-Dependent Feedback Loop Regulates Transient Receptor Potential Vanilloid 4 (TRPV4) Channel Cooperativity and Endothelial Function in Small Pulmonary Arteries. J Am Heart Assoc 2017; 6:JAHA.117.007157. [PMID: 29275372 PMCID: PMC5779028 DOI: 10.1161/jaha.117.007157] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND Recent studies demonstrate that spatially restricted, local Ca2+ signals are key regulators of endothelium-dependent vasodilation in systemic circulation. There are drastic functional differences between pulmonary arteries (PAs) and systemic arteries, but the local Ca2+ signals that control endothelium-dependent vasodilation of PAs are not known. Localized, unitary Ca2+ influx events through transient receptor potential vanilloid 4 (TRPV4) channels, termed TRPV4 sparklets, regulate endothelium-dependent vasodilation in resistance-sized mesenteric arteries via activation of Ca2+-dependent K+ channels. The objective of this study was to determine the unique functional roles, signaling targets, and endogenous regulators of TRPV4 sparklets in resistance-sized PAs. METHODS AND RESULTS Using confocal imaging, custom image analysis, and pressure myography in fourth-order PAs in conjunction with knockout mouse models, we report a novel Ca2+ signaling mechanism that regulates endothelium-dependent vasodilation in resistance-sized PAs. TRPV4 sparklets exhibit distinct spatial localization in PAs when compared with mesenteric arteries, and preferentially activate endothelial nitric oxide synthase (eNOS). Nitric oxide released by TRPV4-endothelial nitric oxide synthase signaling not only promotes vasodilation, but also initiates a guanylyl cyclase-protein kinase G-dependent negative feedback loop that inhibits cooperative openings of TRPV4 channels, thus limiting sparklet activity. Moreover, we discovered that adenosine triphosphate dilates PAs through a P2 purinergic receptor-dependent activation of TRPV4 sparklets. CONCLUSIONS Our results reveal a spatially distinct TRPV4-endothelial nitric oxide synthase signaling mechanism and its novel endogenous regulators in resistance-sized PAs.
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Affiliation(s)
- Corina Marziano
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA.,Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Kwangseok Hong
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Eric L Cope
- Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Michael I Kotlikoff
- Department of Biomedical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
| | - Brant E Isakson
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA.,Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA
| | - Swapnil K Sonkusare
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, VA .,Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, VA.,Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, VA
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9
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Afolayan AJ, Eis A, Alexander M, Michalkiewicz T, Teng RJ, Lakshminrusimha S, Konduri GG. Decreased endothelial nitric oxide synthase expression and function contribute to impaired mitochondrial biogenesis and oxidative stress in fetal lambs with persistent pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2015; 310:L40-9. [PMID: 26519208 DOI: 10.1152/ajplung.00392.2014] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 10/24/2015] [Indexed: 01/23/2023] Open
Abstract
Impaired vasodilation in persistent pulmonary hypertension of the newborn (PPHN) is characterized by mitochondrial dysfunction. We investigated the hypothesis that a decreased endothelial nitric oxide synthase level leads to impaired mitochondrial biogenesis and function in a lamb model of PPHN induced by prenatal ductus arteriosus constriction. We ventilated PPHN lambs with 100% O2 alone or with inhaled nitric oxide (iNO). We treated pulmonary artery endothelial cells (PAECs) from normal and PPHN lambs with detaNONOate, an NO donor. We observed decreased mitochondrial (mt) DNA copy number, electron transport chain (ETC) complex subunit levels, and ATP levels in PAECs and lung tissue of PPHN fetal lambs at baseline compared with gestation matched controls. Phosphorylation of AMP-activated kinase (AMPK) and levels of peroxisome proliferator-activated receptor-γ coactivator 1-α (PGC-1α) and sirtuin-1, which facilitate mitochondrial biogenesis, were decreased in PPHN. Ventilation with 100% O2 was associated with larger decreases in ETC subunits in the lungs of PPHN lambs compared with unventilated PPHN lambs. iNO administration, which facilitated weaning of FiO2 , partly restored mtDNA copy number, ETC subunit levels, and ATP levels. DetaNONOate increased eNOS phosphorylation and its interaction with heat shock protein 90 (HSP90); increased levels of superoxide dismutase 2 (SOD2) mRNA, protein, and activity; and decreased the mitochondrial superoxide levels in PPHN-PAECs. Knockdown of eNOS decreased ETC protein levels in control PAECs. We conclude that ventilation with 100% O2 amplifies oxidative stress and mitochondrial dysfunction in PPHN, which are partly improved by iNO and weaning of oxygen.
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Affiliation(s)
- Adeleye J Afolayan
- Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Annie Eis
- Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Maxwell Alexander
- Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Teresa Michalkiewicz
- Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Ru-Jeng Teng
- Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | | | - Girija G Konduri
- Department of Pediatrics, Children's Research Institute and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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10
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Konduri GG, Afolayan AJ, Eis A, Pritchard KA, Teng RJ. Interaction of endothelial nitric oxide synthase with mitochondria regulates oxidative stress and function in fetal pulmonary artery endothelial cells. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1009-17. [PMID: 26320159 DOI: 10.1152/ajplung.00386.2014] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 08/04/2015] [Indexed: 11/22/2022] Open
Abstract
An increase in oxygen tension at birth is one of the key signals that initiate pulmonary vasodilation in the fetal lung. We investigated the hypothesis that targeting endothelial nitric oxide synthase (eNOS) to the mitochondrial outer membrane regulates reactive oxygen species (ROS) formation in the fetal pulmonary artery endothelial cells (PAEC) during this transition. We isolated PAEC and pulmonary arteries from 137-day gestation fetal lambs (term = 144 days). We exposed PAEC to a simulated transition from fetal to (3% O2) to normoxic (21%) or hyperoxic (95% O2) postnatal Po2 or to the nitric oxide synthase (NOS) agonist ATP. We assessed the effect of O2 and ATP on eNOS interactions with the mitochondrial outer membrane protein porin and with the chaperone hsp90. We also investigated the effect of decoy peptides that blocked eNOS interactions with porin or hsp90 on PAEC angiogenesis and vasodilator function of pulmonary arteries. Transition of fetal PAEC from 3 to 21% O2 but not to 95% O2 or exposure to ATP increased eNOS association with hsp90 and porin. Decoy peptides that blocked eNOS interactions decreased NO release, increased O2 consumption and mitochondrial ROS levels, and impaired PAEC angiogenesis. Decoy peptides also inhibited the relaxation responses of pulmonary artery rings and dilation of resistance size pulmonary arteries to ATP. The mitochondrial-antioxidant mito-ubiquinone restored the response to ATP in decoy peptide-treated pulmonary arteries. These data indicate that targeting eNOS to mitochondria decreases endothelial oxidative stress and facilitates vasodilation in fetal pulmonary circulation at birth.
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Affiliation(s)
- Girija G Konduri
- Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Adeleye J Afolayan
- Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Annie Eis
- Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and
| | - Kirkwood A Pritchard
- Department of Surgery, Division of Pediatric Surgery, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin
| | - Ru-Jeng Teng
- Department of Pediatrics, Cardiovascular Research Center and Children's Research Institute, Medical College of Wisconsin, Milwaukee, Wisconsin; and
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11
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van der Horst IWJM, Reiss I, Tibboel D. Therapeutic targets in neonatal pulmonary hypertension: linking pathophysiology to clinical medicine. Expert Rev Respir Med 2014; 2:85-96. [DOI: 10.1586/17476348.2.1.85] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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12
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Burnstock G, Ralevic V. Purinergic signaling and blood vessels in health and disease. Pharmacol Rev 2013; 66:102-92. [PMID: 24335194 DOI: 10.1124/pr.113.008029] [Citation(s) in RCA: 219] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purinergic signaling plays important roles in control of vascular tone and remodeling. There is dual control of vascular tone by ATP released as a cotransmitter with noradrenaline from perivascular sympathetic nerves to cause vasoconstriction via P2X1 receptors, whereas ATP released from endothelial cells in response to changes in blood flow (producing shear stress) or hypoxia acts on P2X and P2Y receptors on endothelial cells to produce nitric oxide and endothelium-derived hyperpolarizing factor, which dilates vessels. ATP is also released from sensory-motor nerves during antidromic reflex activity to produce relaxation of some blood vessels. In this review, we stress the differences in neural and endothelial factors in purinergic control of different blood vessels. The long-term (trophic) actions of purine and pyrimidine nucleosides and nucleotides in promoting migration and proliferation of both vascular smooth muscle and endothelial cells via P1 and P2Y receptors during angiogenesis and vessel remodeling during restenosis after angioplasty are described. The pathophysiology of blood vessels and therapeutic potential of purinergic agents in diseases, including hypertension, atherosclerosis, ischemia, thrombosis and stroke, diabetes, and migraine, is discussed.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Rowland Hill Street, London NW3 2PF, UK; and Department of Pharmacology, The University of Melbourne, Australia.
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13
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Teng RJ, Wu TJ. Persistent pulmonary hypertension of the newborn. J Formos Med Assoc 2013; 112:177-84. [PMID: 23537863 DOI: 10.1016/j.jfma.2012.11.007] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Revised: 10/01/2012] [Accepted: 11/06/2012] [Indexed: 11/29/2022] Open
Abstract
Persistent pulmonary hypertension of the newborn (PPHN) is a severe pulmonary disorder which occurs at a rate of one in every 500 live births. About 10-50% of the victims will die of the problem and 7-20% of the survivors develop long-term impairments such as hearing deficit, chronic lung disease, and intracranial bleed. Most adult survivors show evidence of augmented pulmonary vasoreactivity, suggesting a phenotypical change. Several animal models have been used to study the pathophysiology and help to develop new therapeutic modality for PPHN. The etiology of PPHN can be classified into three groups: (1) abnormally constricted pulmonary vasculature as a result of parenchymal diseases; (2) hypoplastic pulmonary vasculature; and (3) normal parenchyma with remodeled pulmonary vasculature. Impaired vasorelaxation of pulmonary artery and reduced blood vessel density in lungs are two characteristic findings in PPHN. Medical treatment includes sedation, oxygen, mechanical ventilation, vasorelaxants (inhaled nitric oxide, inhaled or intravenous prostacyclin, intravenous prostaglandin E1, magnesium sulfate), and inotropic agents. Phosphodiesterase inhibitors have recently been studied as another therapeutic agent for PPHN. Endothelin-1 (ET-1) inhibitors have been studied in animals and a case of premature infant with PPHN successfully treated with an ET-I inhibitor has been reported in the literature. Surfactants have been reported as an adjunct treatment for PPHN as a complication of meconium aspiration syndrome. Even with the introduction of several new therapeutic modalities there has been no significant change in survival rate. Extracorporeal membrane oxygenator is used when medical treatment fails and the patient is considered to have a recoverable cause of PPHN.
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Affiliation(s)
- Ru-Jeng Teng
- Division of Neonatology, Department of Pediatrics, Medical College of Wisconsin, Wauwatosa, WI 53226, USA.
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Sharma S, Sun X, Rafikov R, Kumar S, Hou Y, Oishi PE, Datar SA, Raff G, Fineman JR, Black SM. PPAR-γ regulates carnitine homeostasis and mitochondrial function in a lamb model of increased pulmonary blood flow. PLoS One 2012; 7:e41555. [PMID: 22962578 PMCID: PMC3433474 DOI: 10.1371/journal.pone.0041555] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2012] [Accepted: 06/27/2012] [Indexed: 12/11/2022] Open
Abstract
Objective Carnitine homeostasis is disrupted in lambs with endothelial dysfunction secondary to increased pulmonary blood flow (Shunt). Our recent studies have also indicated that the disruption in carnitine homeostasis correlates with a decrease in PPAR-γ expression in Shunt lambs. Thus, this study was carried out to determine if there is a causal link between loss of PPAR-γ signaling and carnitine dysfunction, and whether the PPAR-γ agonist, rosiglitazone preserves carnitine homeostasis in Shunt lambs. Methods and Results siRNA-mediated PPAR-γ knockdown significantly reduced carnitine palmitoyltransferases 1 and 2 (CPT1 and 2) and carnitine acetyltransferase (CrAT) protein levels. This decrease in carnitine regulatory proteins resulted in a disruption in carnitine homeostasis and induced mitochondrial dysfunction, as determined by a reduction in cellular ATP levels. In turn, the decrease in cellular ATP attenuated NO signaling through a reduction in eNOS/Hsp90 interactions and enhanced eNOS uncoupling. In vivo, rosiglitazone treatment preserved carnitine homeostasis and attenuated the development of mitochondrial dysfunction in Shunt lambs maintaining ATP levels. This in turn preserved eNOS/Hsp90 interactions and NO signaling. Conclusion Our study indicates that PPAR-γ signaling plays an important role in maintaining mitochondrial function through the regulation of carnitine homeostasis both in vitro and in vivo. Further, it identifies a new mechanism by which PPAR-γ regulates NO signaling through Hsp90. Thus, PPAR-γ agonists may have therapeutic potential in preventing the endothelial dysfunction in children with increased pulmonary blood flow.
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Affiliation(s)
- Shruti Sharma
- Vascular Biology Center, Georgia Health Sciences University, Augusta, Georgia, United States of America
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15
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Burnstock G, Brouns I, Adriaensen D, Timmermans JP. Purinergic signaling in the airways. Pharmacol Rev 2012; 64:834-68. [PMID: 22885703 DOI: 10.1124/pr.111.005389] [Citation(s) in RCA: 123] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Evidence for a significant role and impact of purinergic signaling in normal and diseased airways is now beyond dispute. The present review intends to provide the current state of knowledge of the involvement of purinergic pathways in the upper and lower airways and lungs, thereby differentiating the involvement of different tissues, such as the epithelial lining, immune cells, airway smooth muscle, vasculature, peripheral and central innervation, and neuroendocrine system. In addition to the vast number of well illustrated functions for purinergic signaling in the healthy respiratory tract, increasing data pointing to enhanced levels of ATP and/or adenosine in airway secretions of patients with airway damage and respiratory diseases corroborates the emerging view that purines act as clinically important mediators resulting in either proinflammatory or protective responses. Purinergic signaling has been implicated in lung injury and in the pathogenesis of a wide range of respiratory disorders and diseases, including asthma, chronic obstructive pulmonary disease, inflammation, cystic fibrosis, lung cancer, and pulmonary hypertension. These ostensibly enigmatic actions are based on widely different mechanisms, which are influenced by the cellular microenvironment, but especially the subtypes of purine receptors involved and the activity of distinct members of the ectonucleotidase family, the latter being potential protein targets for therapeutic implementation.
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Affiliation(s)
- Geoffrey Burnstock
- Autonomic Neuroscience Centre, University College Medical School, Royal Free Campus, London, UK.
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16
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Smolich JJ, Penny DJ, Mynard JP. Increased right ventricular output and central pulmonary reservoir function support rise in pulmonary blood flow during adenosine infusion in the ovine fetus. Am J Physiol Regul Integr Comp Physiol 2012; 302:R1450-7. [PMID: 22513745 DOI: 10.1152/ajpregu.00653.2011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Although adenosine markedly increases fetal pulmonary blood flow, the specific changes in pulmonary trunk (PT), ductus arteriosus (DA), and conduit pulmonary artery (PA) flow interactions that support this increased flow are unknown. To address this issue, seven anesthetized late-gestation fetal sheep were instrumented with PT, DA, and left PA micromanometer catheters and transit-time flow probes. Blood flow profile and wave intensity analyses were performed at baseline and after adenosine infusion to increase PA flow approximately fivefold. With adenosine infusion, DA mean and phasic flows were unchanged, but increases in mean PT (500 ± 256 ml/min, P = 0.002) and the combined left and right PA flow (479 ± 181 ml/min, P < 0.001) were similar (P > 0.7) and related to a larger flow-increasing forward-running compression wave arising from right ventricular (RV) impulsive contraction. Moreover, while the increased PT flow was confined to systole, the rise in PA flow spanned systole (316 ml/min) and diastole (163 ml/min). This elevated PA diastolic flow was accompanied by a 170% greater discharge from a PT and main PA reservoir filled in systole (P < 0.001), but loss of retrograde blood discharge from a conduit PA reservoir that was evident at baseline. These data suggest that 1) an increase in fetal pulmonary blood flow produced by adenosine infusion is primarily supported by a higher PT blood flow (i.e., RV output); 2) about two-thirds of this increased RV output passes into the pulmonary circulation during systole; and 3) the remainder is transiently stored in a central PT and main PA systolic reservoir, from where it discharges into the lungs in diastole.
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Affiliation(s)
- Joseph J Smolich
- Heart Research Group, Murdoch Childrens Research Institute, Flemington Road, Parkville, Victoria 3052, Australia.
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17
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Koos BJ. Adenosine A₂a receptors and O₂ sensing in development. Am J Physiol Regul Integr Comp Physiol 2011; 301:R601-22. [PMID: 21677265 DOI: 10.1152/ajpregu.00664.2010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Reduced mitochondrial oxidative phosphorylation, via activation of adenylate kinase and the resulting exponential rise in the cellular AMP/ATP ratio, appears to be a critical factor underlying O₂ sensing in many chemoreceptive tissues in mammals. The elevated AMP/ATP ratio, in turn, activates key enzymes that are involved in physiologic adjustments that tend to balance ATP supply and demand. An example is the conversion of AMP to adenosine via 5'-nucleotidase and the resulting activation of adenosine A(₂A) receptors, which are involved in acute oxygen sensing by both carotid bodies and the brain. In fetal sheep, A(₂A) receptors associated with carotid bodies trigger hypoxic cardiovascular chemoreflexes, while central A(₂A) receptors mediate hypoxic inhibition of breathing and rapid eye movements. A(₂A) receptors are also involved in hypoxic regulation of fetal endocrine systems, metabolism, and vascular tone. In developing lambs, A(₂A) receptors play virtually no role in O₂ sensing by the carotid bodies, but brain A(₂A) receptors remain critically involved in the roll-off ventilatory response to hypoxia. In adult mammals, A(₂A) receptors have been implicated in O₂ sensing by carotid glomus cells, while central A(₂A) receptors likely blunt hypoxic hyperventilation. In conclusion, A(₂A) receptors are crucially involved in the transduction mechanisms of O₂ sensing in fetal carotid bodies and brains. Postnatally, central A(₂A) receptors remain key mediators of hypoxic respiratory depression, but they are less critical for O₂ sensing in carotid chemoreceptors, particularly in developing lambs.
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Affiliation(s)
- Brian J Koos
- Department of Obstetrics and Gynecology; Brain Research Institute, David Geffen School of Medicine at University of California Los Angeles, Los Angeles, California, USA.
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18
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Fratz S, Fineman JR, Görlach A, Sharma S, Oishi P, Schreiber C, Kietzmann T, Adatia I, Hess J, Black SM. Early determinants of pulmonary vascular remodeling in animal models of complex congenital heart disease. Circulation 2011; 123:916-23. [PMID: 21357846 DOI: 10.1161/circulationaha.110.978528] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Sohrab Fratz
- Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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19
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Xu MH, Gong YS, Su MS, Dai ZY, Dai SS, Bao SZ, Li N, Zheng RY, He JC, Chen JF, Wang XT. Absence of the adenosine A2A receptor confers pulmonary arterial hypertension and increased pulmonary vascular remodeling in mice. J Vasc Res 2010; 48:171-83. [PMID: 20938208 DOI: 10.1159/000316935] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2009] [Accepted: 05/24/2010] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Pulmonary arterial hypertension (PAH) is characterized by sustained elevation of pulmonary vascular resistance resulting from endothelial and smooth muscle cell dysfunction and collagen deposition in pulmonary vascular walls. In this study, we investigated the role of the adenosine A(2A) receptor (A(2A)R) in the development of PAH by determining the effect of genetic inactivation of A(2A)Rs on pulmonary vascular remodeling in mice. METHODS AND RESULTS We characterized hemodynamic, histological and ultrastructural changes in pulmonary vascular remodeling in A(2A)R knockout (KO) mice compared with their wild-type (WT) littermates after exposure to normoxia and hypoxic conditions. After exposure to normoxia, compared to WT mice, A(2A)R KO mice displayed: (1) increased right ventricular systolic pressures and an elevated ratio of the right ventricle over left ventricle plus septum (Fulton index), (2) increased wall area and thickness as well as enhanced smooth muscle actin immunoreactivity in pulmonary resistance vessels, (3) increased proliferating cell nuclear antigen-positive cells in pulmonary resistance vessels and (4) increased smooth muscle cells hypertrophy and collagen deposition in the adventitia of pulmonary arteriole walls as revealed by electron microscope. By contrast, histological analysis revealed no features of hypertensive nephropathy in A(2A)R KO mice and there was no significant difference in systemic blood pressure, and left ventricular masses among the 3 genotypes. Furthermore, following chronic exposure to hypoxia, A(2A)R KO mice exhibited exacerbated elevation in right ventricular systolic pressure, hypertrophy of pulmonary resistance vessels and increased cell proliferation in pulmonary resistance vessels, compared to WT littermates. Thus, genetic inactivation of A(2A)Rs selectively produced PAH and associated increased smooth muscle proliferation and collagen deposition. CONCLUSIONS Extracellular adenosine acting at A(2A)Rs represents an important regulatory mechanism to control the development of PAH and pulmonary vascular remodeling.
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Affiliation(s)
- M H Xu
- The Experimental Neurobiology Research Institute, Wenzhou Medical College, Zhejiang, PR China
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20
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Konduri GG, Bakhutashvili I, Eis A, Gauthier KM. Impaired voltage gated potassium channel responses in a fetal lamb model of persistent pulmonary hypertension of the newborn. Pediatr Res 2009; 66:289-94. [PMID: 19542906 PMCID: PMC3749926 DOI: 10.1203/pdr.0b013e3181b1bc89] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We investigated the hypothesis that oxidative stress in persistent pulmonary hypertension of the newborn (PPHN) impairs voltage gated potassium (Kv) channel function. We induced PPHN in fetal lambs by prenatal ligation of ductus arteriosus; controls had sham ligation. We studied changes in the tone of pulmonary artery (PA) rings and Kv channel current of freshly isolated PA smooth muscle cells (PASMC) using standard techniques. 4-Aminopyridine (4-AP), a Kv channel antagonist, induced dose-dependent constriction of control PA rings; this response was attenuated in PPHN pulmonary arteries. Exogenous superoxide and peroxynitrite inhibited the response to 4-AP in control rings. Tiron, a superoxide scavenger, improved the response to 4-AP in PPHN rings. 4-AP inhibited the NOS-independent relaxation response to ATP in control PA rings. Relaxation response to ATP was blunted in PPHN rings and was improved by NOS antagonist, N-nitro-L-arginine methyl ester (L-NAME). 4-AP attenuated this response in L-NAME-treated PPHN rings. Exogenous superoxide suppressed 4-AP sensitive Kv current in control PASMC. Kv channel current was attenuated in cells from PPHN lambs and was restored by tiron. Oxidative stress impairs Kv channel function in PPHN. Superoxide scavengers may improve pulmonary vasodilation in PPHN in part by restoring Kv channel function.
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Affiliation(s)
- Girija G Konduri
- Department of Pediatrics, Medical College of Wisconsin and Zablocki VA Medical Center, Milwaukee, Wisconsin 53226, USA.
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21
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Glushakova O, Kosugi T, Roncal C, Mu W, Heinig M, Cirillo P, Sánchez-Lozada LG, Johnson RJ, Nakagawa T. Fructose induces the inflammatory molecule ICAM-1 in endothelial cells. J Am Soc Nephrol 2008; 19:1712-20. [PMID: 18508964 DOI: 10.1681/asn.2007121304] [Citation(s) in RCA: 110] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Epidemiologic studies have linked fructose intake with the metabolic syndrome, and it was recently reported that fructose induces an inflammatory response in the rat kidney. Here, we examined whether fructose directly stimulates endothelial inflammatory processes by upregulating the inflammatory molecule intercellular adhesion molecule-1 (ICAM-1). When human aortic endothelial cells were stimulated with physiologic concentrations of fructose, ICAM-1 mRNA and protein expression increased in a time- and dosage-dependent manner, which was independent of NF-kappaB activation. Fructose reduced endothelial nitric oxide (NO) levels and caused a transient reduction in endothelial NO synthase expression. The administration of an NO donor inhibited fructose-induced ICAM-1 expression, whereas blocking NO synthase enhanced it, suggesting that NO inhibits endothelial ICAM-1 expression. Furthermore, fructose resulted in decreased intracellular ATP; administration of exogenous ATP blocked fructose-induced ICAM-1 expression and increased NO levels. Consistent with the in vitro studies, dietary intake of fructose at physiologic dosages increased both serum ICAM-1 concentration and endothelial ICAM-1 expression in the rat kidney. These data suggest that fructose induces inflammatory changes in vascular cells at physiologic concentrations.
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Affiliation(s)
- Olena Glushakova
- Division of Nephrology, Hypertension and Transplantation, University of Florida, P.O. Box 100224, Gainesville, FL 32610-0224, USA
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22
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Chandrasekar I, Eis A, Konduri GG. Betamethasone attenuates oxidant stress in endothelial cells from fetal lambs with persistent pulmonary hypertension. Pediatr Res 2008; 63:67-72. [PMID: 18043518 DOI: 10.1203/pdr.0b013e31815b43ee] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We investigated the effects of betamethasone on oxidative stress and impaired vasodilation in a lamb model of persistent pulmonary hypertension (PPHN). We treated pregnant ewes following fetal ductal ligation with betamethasone or saline for 48 h before delivery. Response of fetal pulmonary arteries to nitric oxide synthase (NOS) agonist adenosine triphosphate (ATP) and nitric oxide (NO) donor, s-nitroso-n-acetyl-penicillamine (SNAP) was determined in tissue bath. Pulmonary artery endothelial cells (PAEC) from fetal lambs with ductal ligation or sham ligation were treated with betamethasone or its vehicle for 48 h. Expression of endothelial NOS (eNOS), endothelin, endothelin-B (ET-B) receptor, and CuZn- and Mn-superoxide dismutase (SOD) in PAEC was studied. Intracellular cGMP and superoxide levels and interaction of eNOS with heat shock protein 90 (Hsp90) were determined in PAEC. Antenatal betamethasone improved the relaxation response of pulmonary arteries to ATP and SNAP in PPHN. PPHN was associated with decreases in eNOS and ET-B receptor and increase in prepro-endothelin mRNA levels. Betamethasone decreased prepro-endothelin mRNA and ET-1 pro-peptide levels and increased eNOS and MnSOD protein levels in PPHN. Betamethasone reversed the increased superoxide/decreased cGMP levels and restored Hsp90-eNOS interactions in PPHN. Betamethasone reduces oxidative stress and improves response of pulmonary arteries to vasodilators in lambs with PPHN.
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Affiliation(s)
- Indira Chandrasekar
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin 53201, USA
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23
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Sharma S, Sud N, Wiseman DA, Carter AL, Kumar S, Hou Y, Rau T, Wilham J, Harmon C, Oishi P, Fineman JR, Black SM. Altered carnitine homeostasis is associated with decreased mitochondrial function and altered nitric oxide signaling in lambs with pulmonary hypertension. Am J Physiol Lung Cell Mol Physiol 2007; 294:L46-56. [PMID: 18024721 DOI: 10.1152/ajplung.00247.2007] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Utilizing aortopulmonary vascular graft placement in the fetal lamb, we have developed a model (shunt) of pulmonary hypertension that mimics congenital heart disease with increased pulmonary blood flow. Our previous studies have identified a progressive development of endothelial dysfunction in shunt lambs that is dependent, at least in part, on decreased nitric oxide (NO) signaling. The purpose of this study was to evaluate the possible role of a disruption in carnitine metabolism in shunt lambs and to determine the effect on NO signaling. Our data indicate that at 2 wk of age, shunt lambs have significantly reduced expression (P < 0.05) of the key enzymes in carnitine metabolism: carnitine palmitoyltransferases 1 and 2 as well as carnitine acetyltransferase (CrAT). In addition, we found that CrAT activity was inhibited due to increased nitration. Furthermore, free carnitine levels were significantly decreased whereas acylcarnitine levels were significantly higher in shunt lambs (P < 0.05). We also found that alterations in carnitine metabolism resulted in mitochondrial dysfunction, since shunt lambs had significantly decreased pyruvate, increased lactate, and a reduced pyruvate/lactate ratio. In pulmonary arterial endothelial cells cultured from juvenile lambs, we found that mild uncoupling of the mitochondria led to a decrease in cellular ATP levels and a reduction in both endothelial NO synthase-heat shock protein 90 (eNOS-HSP90) interactions and NO signaling. Similarly, in shunt lambs we found a loss of eNOS-HSP90 interactions that correlated with a progressive decrease in NO signaling. Our data suggest that mitochondrial dysfunction may play a role in the development of endothelial dysfunction and pulmonary hypertension and increased pulmonary blood flow.
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Affiliation(s)
- Shruti Sharma
- Program in Pulmonary Disease, Vascular Biology Center, Medical College of Georgia, Augusta, GA 30912, USA
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Motti A, Tissot C, Rimensberger PC, Prina-Rousso A, Aggoun Y, Berner M, Beghetti M, da Cruz E. Intravenous adenosine for refractory pulmonary hypertension in a low-weight premature newborn: a potential new drug for rescue therapy. Pediatr Crit Care Med 2006; 7:380-2. [PMID: 16738499 DOI: 10.1097/01.pcc.0000225000.78627.eb] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To use intravenous adenosine as a rescue therapy for neonatal refractory pulmonary hypertension in a low-weight premature infant. STUDY LINE: We report the successful use of a continuous intravenous adenosine infusion in a 1150-g premature baby with severe persistent pulmonary hypertension, refractory to classic management with high-frequency oscillatory ventilation, oxygen therapy and inhaled nitric oxide. RESULTS Adenosine infusion had a dramatic effect allowing for a rapid weaning of oxygen, ventilatory variables, and nitric oxide. CONCLUSIONS Although experience with continuous adenosine infusion is still at an early stage, it might be worth considering its administration as a rescue therapy or even as an alternative to extracorporeal membrane oxygenation.
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Affiliation(s)
- Alessandro Motti
- Service of Pediatric and Neonatal Intensive Care, Department of Pediatrics, Geneva Children's University Hospital, Switzerland
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25
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Abstract
NO produced by NO synthase (NOS) 3 acts as an autacoid to regulate NaCl absorption in the thick ascending limb. ATP induces NO production by NOS 3 in endothelial cells. We hypothesized that extracellular ATP activates NOS in thick ascending limbs through P2 receptors. To test this, we measured intracellular NO production using the NO-selective fluorescent dye DAF-2 in suspensions of rat medullary thick ascending limbs. We found that ATP increased DAF-2 fluorescence in a concentration-dependent manner, reaching saturation at &200 micromol/L with an EC50 of 37 micromol/L. The increase was blunted by 74% by the nonselective NOS inhibitor L-omega-nitro-arginine-methyl-ester (2 mmol/L; 60+/-7 versus 16+/-6 arbitrary fluorescence units; P<0.02; n=5). In the presence of the P2 receptor antagonist suramin (300 micromol/L), ATP-induced NO production was reduced by 64% (101+/-11 versus 37+/-5 arbitrary fluorescence units; P<0.002; n=5). Blocking ATP hydrolysis with a 5'-ectonucleotidase inhibitor, ARL67156 (30 micromol/L) enhanced the response to ATP and shifted the EC(50) to 0.8 micromol/L. In the presence of ARL67156, the EC50 of the P2X-selective agonist beta,gamma-methylene-adenosine 5'-triphosphate was 4.8 micromol/L and the EC50 for the P2Y-selective agonist UTP was 40.4 micromol/L. The maximal responses for both agonists were similar. Taken together, these data indicate that ATP stimulates NO production in the thick ascending limb primarily through P2X receptor activation and that ATP hydrolysis may regulate NO production.
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Affiliation(s)
- Guillermo Silva
- Division of Hypertension and Vascular Research, Henry Ford Hospital, Detroit, MI 48202, USA
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26
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Deruelle P, Grover TR, Storme L, Abman SH. Effects of BAY 41-2272, a soluble guanylate cyclase activator, on pulmonary vascular reactivity in the ovine fetus. Am J Physiol Lung Cell Mol Physiol 2004; 288:L727-33. [PMID: 15608146 DOI: 10.1152/ajplung.00409.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Nitric oxide (NO)-cGMP signaling plays a critical role during the transition of the pulmonary circulation at birth. BAY 41-2272 is a novel NO-independent direct stimulator of soluble guanylate cyclase that causes vasodilation in systemic and local circulations. However, the hemodynamic effects of BAY 41-2272 have not been studied in the perinatal pulmonary circulation. We hypothesized that BAY 41-2272 causes potent and sustained fetal pulmonary vasodilation. We performed surgery on 14 fetal lambs (125-130 days gestation; 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 (LPA) to measure blood flow, and a catheter was placed in the LPA for drug infusion. Pulmonary vascular resistance (PVR) was calculated as pulmonary artery pressure minus left atrial pressure divided by LPA blood flow. BAY 41-2272 caused dose-related increases in pulmonary blood flow up to threefold above baseline and reduced PVR by 75% (P < 0.01). Prolonged infusion of BAY 41-2272 caused sustained pulmonary vasodilation throughout the 120-min infusion period. The pulmonary vasodilator effect of BAY 41-2272 was not attenuated by N(omega)-nitro-l-arginine, a NO synthase inhibitor. In addition, compared with sildenafil, a phosphodiesterase 5 inhibitor, the pulmonary vasodilator response to BAY 41-2272 was more prolonged. We conclude that BAY 41-2272 causes potent and sustained fetal pulmonary vasodilation independent of NO release. We speculate that BAY 41-2272 may have therapeutic potential for pulmonary hypertension associated with failure to circulatory adaptation at birth, especially in the setting of impaired NO production.
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Affiliation(s)
- Philippe Deruelle
- Pediatric Heart Lung Center, University of Colorado School of Medicine, Denver, CO 80218-1088, USA
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27
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Konduri GG, Bakhutashvili I, Frenn R, Chandrasekhar I, Jacobs ER, Khanna AK. P2Y purine receptor responses and expression in the pulmonary circulation of juvenile rabbits. Am J Physiol Heart Circ Physiol 2004; 287:H157-64. [PMID: 14962841 DOI: 10.1152/ajpheart.00617.2003] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purine nucleotide ATP mediates pulmonary vasodilation at birth by stimulation of P2Y purine receptors in the pulmonary circulation. The specific P2Y receptors in the pulmonary circulation and the segmental distribution of their responses remain unknown. We investigated the effects of purine nucleotides, ATP, ADP, and AMP, and pyrimidine nucleotides, UTP, UDP, and UMP, in juvenile rabbit pulmonary arteries for functional characterization of P2Y receptors. We also studied the expression of P2Y receptor subtypes in pulmonary arteries and the role of nitric oxide (NO), prostaglandins, and cytochrome P-450 metabolites in the response to ATP. In conduit size arteries, ATP, ADP, and AMP caused greater relaxation responses than UTP, UDP, and UMP. In resistance vessels, ATP and UTP caused comparable vasodilation. The response to ATP was attenuated by the P2Y antagonist cibacron blue, the NO synthase antagonist N(omega)-nitro-l-arginine methyl ester (l-NAME), and the cytochrome P-450 inhibitor 17-octadecynoic acid but not by the P2X antagonist alpha,beta-methylene ATP or the cyclooxygenase inhibitor indomethacin in conduit arteries. In the resistance vessels, l-NAME caused a more complete inhibition of the responses to ATP and UTP. Responses to AMP and UMP were NO and endothelium dependent, whereas responses to ADP and UDP were NO and endothelium independent in the conduit arteries. RT-PCR showed expression of P2Y(1), P2Y(2), and P2Y(4) receptors, but not P2Y(6) receptors, in lung parenchyma, pulmonary arteries, and pulmonary artery endothelial cells. These data suggest that distinct P2Y receptors mediate the vasodilator responses to purine and pyrimidine nucleotides in the juvenile rabbit pulmonary circulation. ATP appears to cause NO-mediated vasodilation predominantly through P2Y2 receptors on endothelium.
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Affiliation(s)
- Girija G Konduri
- Department of Pediatrics, Medical College of Wisconsin, CHW OB 213 A, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
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Oishi P, Fineman JR. Pharmacologic therapy for persistent pulmonary hypertension of the newborn: as "poly" as the disease itself. Pediatr Crit Care Med 2004; 5:94-6. [PMID: 14709984 DOI: 10.1097/01.pcc.0000103193.92228.39] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Sprague RS, Olearczyk JJ, Spence DM, Stephenson AH, Sprung RW, Lonigro AJ. Extracellular ATP signaling in the rabbit lung: erythrocytes as determinants of vascular resistance. Am J Physiol Heart Circ Physiol 2003; 285:H693-700. [PMID: 12689860 DOI: 10.1152/ajpheart.01026.2002] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previously, it was reported that red blood cells (RBCs) are required to demonstrate participation of nitric oxide (NO) in the regulation of rabbit pulmonary vascular resistance (PVR). RBCs do not synthesize NO; hence, we postulated that ATP, present in millimolar amounts in RBCs, was the mediator, which evoked NO synthesis in the vascular endothelium. First, we found that deformation of RBCs, as occurs on passage across the pulmonary circulation with increasing flow rate, evoked increments in ATP release. Here, ATP (300 nM), administered to isolated, salt solution-perfused (PSS) rabbit lungs, decreased total and upstream (arterial) PVR, a response inhibited by NG-nitro-L-arginine methyl ester (L-NAME, 100 microM). In lungs perfused with PSS containing RBCs, L-NAME increased total and upstream PVR. In lungs perfused with PSS containing glibenclamide-treated RBCs, which inhibits ATP release, L-NAME was without effect. Apyrase grade VII (8 U/ml), which degrades ATP to AMP, was without effect on PVR in PSS-perfused lungs. These results are consistent with the hypothesis that ATP, released from RBCs as they traverse the pulmonary circulation, evokes endogenous NO synthesis.
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Affiliation(s)
- Randy S Sprague
- Department of Pharmacological and Physiological Science, School of Medicine, Saint Louis University, 1402 South Grand Blvd., St. Louis, MO 63104, USA.
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Konduri GG, Ou J, Shi Y, Pritchard KA. Decreased association of HSP90 impairs endothelial nitric oxide synthase in fetal lambs with persistent pulmonary hypertension. Am J Physiol Heart Circ Physiol 2003; 285:H204-11. [PMID: 12663260 DOI: 10.1152/ajpheart.00837.2002] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Persistent pulmonary hypertension of newborn (PPHN) is associated with decreased nitric oxide (NO) release and impaired pulmonary vasodilation. We investigated the hypothesis that decreased association of heat shock protein 90 (HSP90) with endothelial NO synthase (eNOS) impairs NO release and vasodilation in PPHN. The responses to the NOS agonist ATP were investigated in fetal lambs with PPHN induced by prenatal ligation of ductus arteriosus, and in sham ligation controls. ATP caused dose-dependent vasodilation in control pulmonary resistance arteries, and this response was attenuated in PPHN vessels. The response of control pulmonary arteries to ATP was attenuated by NG-nitro-l-arginine methyl ester (l-NAME), a NOS antagonist, and geldanamycin, an inhibitor of HSP90-eNOS interaction. The attenuated response to ATP observed in PPHN was improved by pretreatment of vessels with l-NAME or 4,5-dihydroxy-1,3-benzene-disulfonate, a superoxide scavenger. Pulmonary arteries from PPHN lambs had decreased basal levels of HSP90 in association with eNOS. Association of HSP90 with eNOS and NO release increased in response to ATP in control pulmonary artery endothelial cells, but not in cells from PPHN lambs. Decreased HSP90-eNOS interactions may contribute to the impaired NO release and vasodilation observed in the ductal ligation model of PPHN.
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Affiliation(s)
- Girija G Konduri
- Department of Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Konduri GG, Mattei J. Role of oxidative phosphorylation and ATP release in mediating birth-related pulmonary vasodilation in fetal lambs. Am J Physiol Heart Circ Physiol 2002; 283:H1600-8. [PMID: 12234814 DOI: 10.1152/ajpheart.00245.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the hypothesis that birth-related pulmonary vasodilation is mediated in part by an increase in oxidative phosphorylation and ATP release in response to oxygen exposure at birth. Studies were done in fetal lambs to evaluate the independent effects of oxygen, lung distension alone, or lung distension accompanied by oxygenation and shear stress on fetal pulmonary blood flow and resistance and plasma ATP levels in the pulmonary artery. The effect of each intervention was evaluated in lambs assigned to one of three groups: control or pretreatment with 2,4-dinitrophenol or antimycin-A, inhibitors of oxidative phosphorylation. Exposure to oxygen alone or with lung distension was associated with increases in plasma ATP levels and pulmonary blood flow and a decrease in pulmonary vascular resistance. Plasma ATP levels did not change during lung distension alone. 2,4-Dinitrophenol and antimycin-A attenuated the pulmonary vasodilator response to oxygen but did not attenuate the response to lung distension alone. An increase in oxidative phosphorylation and ATP release during oxygen exposure may contribute to birth-related pulmonary vasodilation in fetal lambs.
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Affiliation(s)
- Girija G Konduri
- Department of Pediatrics and Cardiovascular Research Center, Medical College of Wisconsin, Milwaukee 53226, USA.
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