1
|
Forbes LM, Bull TM, Lahm T, Sisson T, O’Gean K, Lawley JS, Hunter K, Levine BD, Lovering A, Roach RC, Subudhi AW, Cornwell WK. Right ventricular performance during acute hypoxic exercise. J Physiol 2024:10.1113/JP284943. [PMID: 38409819 PMCID: PMC11345882 DOI: 10.1113/jp284943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 02/01/2024] [Indexed: 02/28/2024] Open
Abstract
Acute hypoxia increases pulmonary arterial (PA) pressures, though its effect on right ventricular (RV) function is controversial. The objective of this study was to characterize exertional RV performance during acute hypoxia. Ten healthy participants (34 ± 10 years, 7 males) completed three visits: visits 1 and 2 included non-invasive normoxic (fraction of inspired oxygen (F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$ ) = 0.21) and isobaric hypoxic (F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$ = 0.12) cardiopulmonary exercise testing (CPET) to determine normoxic/hypoxic maximal oxygen uptake (V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ ). Visit 3 involved invasive haemodynamic assessments where participants were randomized 1:1 to either Swan-Ganz or conductance catheterization to quantify RV performance via pressure-volume analysis. Arterial oxygen saturation was determined by blood gas analysis from radial arterial catheterization. During visit 3, participants completed invasive submaximal CPET testing at 50% normoxicV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ and again at 50% hypoxicV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ (F i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$ = 0.12). Median (interquartile range) values for non-invasiveV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ values during normoxic and hypoxic testing were 2.98 (2.43, 3.66) l/min and 1.84 (1.62, 2.25) l/min, respectively (P < 0.0001). Mean PA pressure increased significantly when transitioning from rest to submaximal exercise during normoxic and hypoxic conditions (P = 0.0014). Metrics of RV contractility including preload recruitable stroke work, dP/dtmax , and end-systolic pressure increased significantly during the transition from rest to exercise under normoxic and hypoxic conditions. Ventricular-arterial coupling was maintained during normoxic exercise at 50%V ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ . During submaximal exercise at 50% of hypoxicV ̇ O 2 max ${\dot V_{{{\mathrm{O}}_{\mathrm{2}}}{\mathrm{max}}}}$ , ventricular-arterial coupling declined but remained within normal limits. In conclusion, resting and exertional RV functions are preserved in response to acute exposure to hypoxia at anF i O 2 ${F_{{\mathrm{i}}{{\mathrm{O}}_{\mathrm{2}}}}}$ = 0.12 and the associated increase in PA pressures. KEY POINTS: The healthy right ventricle augments contractility, lusitropy and energetics during periods of increased metabolic demand (e.g. exercise) in acute hypoxic conditions. During submaximal exercise, ventricular-arterial coupling decreases but remains within normal limits, ensuring that cardiac output and systemic perfusion are maintained. These data describe right ventricular physiological responses during submaximal exercise under conditions of acute hypoxia, such as occurs during exposure to high altitude and/or acute hypoxic respiratory failure.
Collapse
Affiliation(s)
- Lindsay M. Forbes
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado, Aurora, Colorado, United States
| | - Todd M. Bull
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado, Aurora, Colorado, United States
| | - Tim Lahm
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado, Aurora, Colorado, United States
- Division of Pulmonary, Critical Care and Sleep Medicine, National Jewish Health, Denver, Colorado, United States
- Rocky Mountain Regional Veterans Affairs Medical Center, Aurora, Colorado, United States
| | - Tyler Sisson
- Clinical Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora CO
| | - Katie O’Gean
- Clinical Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora CO
| | - Justin S. Lawley
- Department of Sport Science, University of Innsbruck, Innsbruck Austria
- Institute of Mountain Emergency Medicine, Eurac Research, Bolzano, Italy
| | - Kendall Hunter
- Department of Bioengineering, University of Colorado Anschutz Medical Campus, Aurora CO
| | - Benjamin D. Levine
- Division of Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas
- Texas Health Presbyterian Hospital, Institute for Exercise and Environmental Medicine, Dallas TX
| | | | - Robert C. Roach
- Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado, Aurora, Colorado, United States
| | - Andrew W. Subudhi
- Department of Physiology, University of Colorado, Colorado Springs, Colorado, United States
| | - William K. Cornwell
- Clinical Translational Research Center, University of Colorado Anschutz Medical Campus, Aurora CO
- Division of Cardiology, Department of Medicine. University of Colorado, Aurora, Colorado, United States
| |
Collapse
|
2
|
Oliveira RKF, Nyasulu PS, Iqbal AA, Hamdan Gul M, Ferreira EVM, Leclair JW, Htun ZM, Howard LS, Mocumbi AO, Bryant AJ, Tamuzi JL, Avdeev S, Petrosillo N, Hassan A, Butrous G, de Jesus Perez V. Cardiopulmonary disease as sequelae of long-term COVID-19: Current perspectives and challenges. Front Med (Lausanne) 2022; 9:1041236. [PMID: 36530872 PMCID: PMC9748443 DOI: 10.3389/fmed.2022.1041236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2022] [Accepted: 11/14/2022] [Indexed: 12/03/2022] Open
Abstract
COVID-19 infection primarily targets the lungs, which in severe cases progresses to cytokine storm, acute respiratory distress syndrome, multiorgan dysfunction, and shock. Survivors are now presenting evidence of cardiopulmonary sequelae such as persistent right ventricular dysfunction, chronic thrombosis, lung fibrosis, and pulmonary hypertension. This review will summarize the current knowledge on long-term cardiopulmonary sequelae of COVID-19 and provide a framework for approaching the diagnosis and management of these entities. We will also identify research priorities to address areas of uncertainty and improve the quality of care provided to these patients.
Collapse
Affiliation(s)
- Rudolf K. F. Oliveira
- Division of Respiratory Diseases, Department of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
- *Correspondence: Rudolf K. F. Oliveira,
| | - Peter S. Nyasulu
- Division of Epidemiology and Biostatistics, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Adeel Ahmed Iqbal
- National Health System (NHS), Global Clinical Network, London, United Kingdom
| | - Muhammad Hamdan Gul
- Department of Internal Medicine, University of Kentucky, Lexington, KY, United States
| | - Eloara V. M. Ferreira
- Division of Respiratory Diseases, Department of Medicine, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | | | - Zin Mar Htun
- Division of Pulmonary and Critical Care, National Institute of Health, University of Maryland, College Park, College Park, MD, United States
| | - Luke S. Howard
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Ana O. Mocumbi
- Faculty of Medicine, Universidade Eduardo Mondlane, Maputo, Mozambique
- Non-communicable Diseases Division, Instituto Nacional de Saúde, Marracuene, Mozambique
| | - Andrew J. Bryant
- College of Medicine, University of Florida, Gainesville, FL, United States
| | - Jacques L. Tamuzi
- Division of Epidemiology and Biostatistics, Department of Global Health, Faculty of Medicine and Health Sciences, Stellenbosch University, Stellenbosch, South Africa
| | - Sergey Avdeev
- Department of Pulmonology, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia
| | - Nicola Petrosillo
- Infection Prevention and Control-Infectious Disease Service, Foundation University Hospital Campus Bio-Medico, Rome, Italy
| | - Ahmed Hassan
- Department of Cardiology, Cairo University, Cairo, Egypt
| | - Ghazwan Butrous
- Medway School of Pharmacy, University of Kent at Canterbury, Canterbury, United Kingdom
| | - Vinicio de Jesus Perez
- Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University Medical Center, Stanford, CA, United States
| |
Collapse
|
3
|
Spyropoulos F, Vitali SH, Touma M, Rose CD, Petty CR, Levy P, Kourembanas S, Christou H. Echocardiographic markers of pulmonary hemodynamics and right ventricular hypertrophy in rat models of pulmonary hypertension. Pulm Circ 2020; 10:2045894020910976. [PMID: 32537128 PMCID: PMC7268140 DOI: 10.1177/2045894020910976] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 02/11/2020] [Indexed: 01/05/2023] Open
Abstract
Echocardiography is the gold standard non-invasive technique to diagnose
pulmonary hypertension. It is also an important modality used to monitor disease
progression and response to treatment in patients with pulmonary hypertension.
Surprisingly, only few studies have been conducted to validate and standardize
echocardiographic parameters in experimental animal models of pulmonary
hypertension. We sought to define cut-off values for both invasive and
non-invasive measures of pulmonary hemodynamics and right ventricular
hypertrophy that would reliably diagnose pulmonary hypertension in three
different rat models. The study was designed in two phases: (1) a
derivation phase to establish the cut-off values for
invasive measures of right ventricular systolic pressure, Fulton's index (right
ventricular weight/left ventricle + septum weight), right ventricular to body
weight ratio, and non-invasive echocardiographic measures of pulmonary arterial
acceleration time, pulmonary arterial acceleration time to ejection time ratio
and right ventricular wall thickness in diastole in the hypoxic and
monocrotaline rat models of pulmonary hypertension and (2) a validation
phase to test the performance of the cut-off values in predicting
pulmonary hypertension in an independent cohort of rats with
Sugen/hypoxia-induced pulmonary hypertension. Our study demonstrates that right
ventricular systolic pressure ≥35.5 mmHg and Fulton's Index ≥0.34 are highly
sensitive (>94%) and specific (>91%) cut-offs to distinguish animals with
pulmonary hypertension from controls. When pulmonary arterial acceleration
time/ejection time and right ventricular wall thickness in diastole were both
measured, a result of either pulmonary arterial acceleration time/ejection time
≤0.25 or right ventricular wall thickness in diastole ≥1.03 mm detected right
ventricular systolic pressure ≥35.5 mmHg or Fulton's Index ≥0.34 with a
sensitivity of 88% and specificity of 100%. With properly validated non-invasive
echocardiography measures of right ventricular performance in rats that
accurately predict invasive measures of pulmonary hemodynamics, future studies
can now utilize these markers to test the efficacy of different treatments with
preclinical therapeutic modeling.
Collapse
Affiliation(s)
- Fotios Spyropoulos
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, MA, USA
| | - Sally H Vitali
- Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Boston, MA, USA
| | - Marlin Touma
- University of California at Los Angeles, Los Angeles, CA, USA
| | - Chase D Rose
- Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | - Carter R Petty
- Institutional Centers for Clinical and Translational Research, Boston Children's Hospital, Boston, MA, USA
| | - Philip Levy
- Department of Pediatrics, Boston Children's Hospital, Boston, MA, USA
| | | | - Helen Christou
- Department of Pediatric Newborn Medicine, Brigham and Women's Hospital, Boston, MA, USA
| |
Collapse
|
4
|
Antigny F, Mercier O, Humbert M, Sabourin J. Excitation-contraction coupling and relaxation alteration in right ventricular remodelling caused by pulmonary arterial hypertension. Arch Cardiovasc Dis 2020; 113:70-84. [DOI: 10.1016/j.acvd.2019.10.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 10/18/2019] [Accepted: 10/23/2019] [Indexed: 02/09/2023]
|
5
|
Salubrinal attenuates right ventricular hypertrophy and dysfunction in hypoxic pulmonary hypertension of rats. Vascul Pharmacol 2016; 87:190-198. [DOI: 10.1016/j.vph.2016.09.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Revised: 08/16/2016] [Accepted: 09/23/2016] [Indexed: 11/23/2022]
|
6
|
Egemnazarov B, Schmidt A, Crnkovic S, Sydykov A, Nagy BM, Kovacs G, Weissmann N, Olschewski H, Olschewski A, Kwapiszewska G, Marsh LM. Pressure Overload Creates Right Ventricular Diastolic Dysfunction in a Mouse Model: Assessment by Echocardiography. J Am Soc Echocardiogr 2015; 28:828-43. [PMID: 25840639 DOI: 10.1016/j.echo.2015.02.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Indexed: 10/23/2022]
Abstract
BACKGROUND Noninvasive diagnostic tools for right ventricular (RV) dysfunction measurements are increasingly being used, although their association with the pathologic mechanisms of dysfunction is poorly understood. Although investigations have focused mainly on RV systolic function, RV diastolic function remains mostly neglected. The aim of this study was to test which echocardiographic parameters best reflect RV diastolic function in mice. METHODS Pulmonary artery banding (PAB) was used to induce RV pressure overload in mice. Transthoracic echocardiography and invasive hemodynamic measurements were performed after 3 weeks in PAB and sham-operated mice. Subsequently, the hearts were investigated by histology and analyzed for gene expression. RESULTS PAB-induced pressure overload (RV systolic pressure PAB 52.6 ± 11.8 mm Hg vs sham 27.0 ± 2.7 mm Hg) resulted in RV hypertrophy and remodeling, as reflected by increased Fulton index (PAB 0.37 ± 0.05 vs sham 0.25 ± 0.02, P = .001). Masson's trichrome staining revealed increased interstitial fibrosis (PAB 12.25 ± 3.12% vs sham 3.97 ± 1.58%, P = .002). This was associated with significant systolic RV dysfunction as demonstrated by reduced contractility index and diastolic dysfunction as demonstrated by end-diastolic pressure (PAB 2.66 ± 0.83 mm Hg vs sham 1.49 ± 0.50 mm Hg, P < .001) and τ (PAB 40.0 ± 16.1 msec vs sham 13.0 ± 3.5 msec, P < .001). Messenger ribonucleic acid expression of β-myosin heavy chain, atrial and brain natriuretic peptides, collagen family members was elevated, and the sarco/endoplasmic reticulum Ca(2+)-ATPase was decreased. Echocardiography revealed significant increases in RV free wall thickness and isovolumic relaxation time and a decrease in left ventricular eccentricity index, E', and tricuspid annular plane systolic excursion. Isovolumic relaxation time and E' were significantly correlated with end-diastolic pressure (rs = 0.511 and -0.451) and τ (rs = 0.739 and -0.445, respectively). Moreover, E' was negatively correlated with the degree of RV fibrosis (rs = -0.717). CONCLUSIONS Within 3 weeks, PAB causes pressure overload-induced RV hypertrophy and remodeling with compensated systolic and diastolic dysfunction in mice. RV free wall thickness, tricuspid annular plane systolic excursion, E', E/E' ratio, and isovolumic relaxation time appear to be the most reliable echocardiographic parameters for the assessment of RV dysfunction.
Collapse
Affiliation(s)
| | - Albrecht Schmidt
- Division of Cardiology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Slaven Crnkovic
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| | - Akylbek Sydykov
- University of Giessen and Marburg Lung Center, Excellence Cluster Cardio-Pulmonary System, Giessen, Germany
| | - Bence M Nagy
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Gabor Kovacs
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Norbert Weissmann
- University of Giessen and Marburg Lung Center, Excellence Cluster Cardio-Pulmonary System, Giessen, Germany
| | - Horst Olschewski
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, Graz, Austria
| | - Andrea Olschewski
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Experimental Anesthesiology, Department of Anesthesia and Intensive Care Medicine, Medical University of Graz, Graz, Austria
| | - Grazyna Kwapiszewska
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria; Experimental Anesthesiology, Department of Anesthesia and Intensive Care Medicine, Medical University of Graz, Graz, Austria
| | - Leigh M Marsh
- Ludwig Boltzmann Institute for Lung Vascular Research, Graz, Austria
| |
Collapse
|
7
|
Vitali SH, Hansmann G, Rose C, Fernandez-Gonzalez A, Scheid A, Mitsialis SA, Kourembanas S. The Sugen 5416/hypoxia mouse model of pulmonary hypertension revisited: long-term follow-up. Pulm Circ 2015; 4:619-29. [PMID: 25610598 DOI: 10.1086/678508] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Accepted: 03/31/2014] [Indexed: 12/27/2022] Open
Abstract
The combination of a vascular endothelial growth factor receptor antagonist, Sugen 5416 (SU5416), and chronic hypoxia is known to cause pronounced pulmonary hypertension (PH) with angioobliterative lesions in rats and leads to exaggerated PH in mice as well. We sought to determine whether weekly SU5416 injections during 3 weeks of hypoxia leads to long-term development of angioobliterative lesions and sustained or progressive PH in mice. Male C57BL/6J mice were injected with SU5416 (SuHx) or vehicle (VehHx) weekly during 3 weeks of exposure to 10% oxygen. Echocardiographic and invasive measures of hemodynamics and pulmonary vascular morphometry were performed after the 3-week hypoxic exposure and after 10 weeks of recovery in normoxia. SuHx led to higher right ventricular (RV) systolic pressure and RV hypertrophy than VehHx after 3 weeks of hypoxia. Ten weeks after hypoxic exposure, RV systolic pressure decreased but remained elevated in SuHx mice compared with VehHx or normoxic control mice, but RV hypertrophy had resolved. After 3 weeks of hypoxia and 10 weeks of follow-up in normoxia, tricuspid annular plane systolic excursion was significantly decreased, indicating decreased systolic RV function. Very few angioobliterative lesions were found at the 10-week follow-up time point in SuHx mouse lungs. In conclusion, SU5416 combined with 3 weeks of hypoxia causes a more profound PH phenotype in mice than hypoxia alone. PH persists over 10 weeks of normoxic follow-up in SuHx mice, but significant angioobliterative lesions do not occur, and neither PH nor RV dysfunction worsens. The SuHx mouse model is a useful adjunct to other PH models, but the search will continue for a mouse model that better recapitulates the human phenotype.
Collapse
Affiliation(s)
- Sally H Vitali
- Department of Anesthesia, Perioperative, and Pain Medicine, Division of Critical Care Medicine, Boston Children's Hospital, Boston, Massachusetts, USA ; SHV and GH contributed equally to this work
| | - Georg Hansmann
- Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA ; Department of Pediatric Cardiology and Critical Care, Hannover Medical School, Hannover, Germany ; SHV and GH contributed equally to this work
| | - Chase Rose
- Department of Anesthesia, Perioperative, and Pain Medicine, Division of Critical Care Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Angeles Fernandez-Gonzalez
- Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Annette Scheid
- Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - S Alex Mitsialis
- Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Stella Kourembanas
- Department of Medicine, Division of Newborn Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| |
Collapse
|
8
|
Transmural dispersion of repolarization and cardiac remodeling in ventricles of rabbit with right ventricular hypertrophy. J Pharmacol Toxicol Methods 2014; 71:129-36. [PMID: 25305588 DOI: 10.1016/j.vascn.2014.09.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 09/26/2014] [Accepted: 09/30/2014] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Recent publications demonstrated that rabbits with right ventricular hypertrophy (RVH) possess high sensitivity and specificity for drug-induced arrhythmias. However, the underlying mechanism has not been elucidated. This study aimed to evaluate RVH induced changes in cardiac remodeling especially the transmural dispersion of repolarization (TDR), epicardial monophasic action potentials (MAP), and hERG mRNA expression in rabbits. METHODS New Zealand White rabbits (n=13) were divided into 2 groups: sham operated (SHAM, n=6) and pulmonary artery banding (PAB, n=7). PAB was induced by narrowing the pulmonary artery. Twenty weeks after surgery, hemodynamic, cardiac function, electrocardiograms, and MAP were obtained from PAB compared with SHAM. After measurement, rabbits were sacrificed to collect ventricular myocardium for histopathological analysis and measurement of hERG mRNA expression by real time PCR. RESULTS After 20weeks, the % HW to BW ratio of whole heart and right ventricle (RV) and left and right ventricular free wall thickness was significantly increased in PAB when compared with those in SHAM. PAB has a significant electrical remodeling as demonstrated by lengthening of QT, QTc intervals, and increased Tp-Te duration. PAB also has a significant functional remodeling verified by decreased contractility index of RV and lengthened time constant of relaxation of LV. MAP of RV epicardium was significantly shortened in PAB consistently with increased hERG mRNA expression at the epicardium of RV. DISCUSSION The rabbit with PAB demonstrates cardiac remodeling diastolic and systolic dysfunctions. These rabbits also demonstrate increased TDR and electrical remodeling related to the change of hERG mRNA expression which may be prone to develop arrhythmias.
Collapse
|
9
|
Dumas de la Roque E, Quignard JF, Ducret T, Dahan D, Courtois A, Begueret H, Marthan R, Savineau JP. Beneficial effect of dehydroepiandrosterone on pulmonary hypertension in a rodent model of pulmonary hypertension in infants. Pediatr Res 2013; 74:163-9. [PMID: 23648417 DOI: 10.1038/pr.2013.73] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 12/19/2012] [Indexed: 11/09/2022]
Abstract
BACKGROUND Pulmonary hypertension (PH) is a disease that affects the adult or infant population. Dehydroepiandrosterone (DHEA), a steroid hormone, has been previously shown to prevent and to reverse PH in an adult rat model. We thus investigated its effect in a rat-pup model of chronic hypoxic PH. METHODS Animals were maintained for 3 wk in a hypobaric chamber to induce PH, with or without concomitant treatment with DHEA (30 mg/kg every alternate day). RESULTS DHEA significantly reduced mean pulmonary artery pressure (measured by right cardiac catheterization), pulmonary artery remodeling (evaluated by histology), and right-ventricular hypertrophy (measured by echography and by the Fulton index). At the level of the pulmonary artery smooth muscle cell (PASMC), DHEA increased activity and expression of the large-conductance Ca2+-activated potassium channel (BKCa) (assessed by means of the patch clamp technique). DHEA also inhibited both serotonin- and KCl-induced contraction and smooth muscle cell proliferation. CONCLUSION Collectively, these results indicate that DHEA prevents PH in infant rats and may therefore be clinically relevant for the management of PH in human infants.
Collapse
|
10
|
Forrest AS, Joyce TC, Huebner ML, Ayon RJ, Wiwchar M, Joyce J, Freitas N, Davis AJ, Ye L, Duan DD, Singer CA, Valencik ML, Greenwood IA, Leblanc N. Increased TMEM16A-encoded calcium-activated chloride channel activity is associated with pulmonary hypertension. Am J Physiol Cell Physiol 2012; 303:C1229-43. [PMID: 23034390 DOI: 10.1152/ajpcell.00044.2012] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Pulmonary artery smooth muscle cells (PASMCs) are more depolarized and display higher Ca(2+) levels in pulmonary hypertension (PH). Whether the functional properties and expression of Ca(2+)-activated Cl- channels (Cl(Ca)), an important excitatory mechanism in PASMCs, are altered in PH is unknown. The potential role of Cl(Ca) channels in PH was investigated using the monocrotaline (MCT)-induced PH model in the rat. Three weeks postinjection with a single dose of MCT (50 mg/kg ip), the animals developed right ventricular hypertrophy (heart weight measurements) and changes in pulmonary arterial flow (pulse-waved Doppler imaging) that were consistent with increased pulmonary arterial pressure and PH. Whole cell patch experiments revealed an increase in niflumic acid (NFA)-sensitive Ca(2+)-activated Cl(-) current [I(Cl(Ca))] density in PASMCs from large conduit and small intralobar pulmonary arteries of MCT-treated rats vs. aged-matched saline-injected controls. Quantitative RT-PCR and Western blot analysis revealed that the alterations in I(Cl(Ca)) were accompanied by parallel changes in the expression of TMEM16A, a gene recently shown to encode for Cl(Ca) channels. The contraction to serotonin of conduit and intralobar pulmonary arteries from MCT-treated rats exhibited greater sensitivity to nifedipine (1 μM), an l-type Ca(2+) channel blocker, and NFA (30 or 100 μM, with or without 10 μM indomethacin to inhibit cyclooxygenases) or T16A(Inh)-A01 (10 μM), TMEM16A/Cl(Ca) channel inhibitors, than that of control animals. In conclusion, augmented Cl(Ca)/TMEM16A channel activity is a major contributor to the changes in electromechanical coupling of PA in this model of PH. TMEM16A-encoded channels may therefore represent a novel therapeutic target in this disease.
Collapse
Affiliation(s)
- Abigail S Forrest
- Department of Pharmacology, University of Nevada School of Medicine, Reno, Nevada 89557-0573, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Nouette-Gaulain K, Biais M, Savineau JP, Marthan R, Mazat JP, Letellier T, Sztark F. Chronic hypoxia-induced alterations in mitochondrial energy metabolism are not reversible in rat heart ventricles. Can J Physiol Pharmacol 2011; 89:58-66. [PMID: 21186378 DOI: 10.1139/y10-105] [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
Chronic hypoxia alters mitochondrial energy metabolism. In the heart, oxidative capacity of both ventricles is decreased after 3 weeks of chronic hypoxia. The aim of this study was to evaluate the reversal of these metabolic changes upon normoxia recovery. Rats were exposed to a hypobaric environment for 3 weeks and then subjected to a normoxic environment for 3 weeks (normoxia-recovery group) and compared with rats maintained in a normoxic environment (control group). Mitochondrial energy metabolism was differentially examined in both left and right ventricles. Oxidative capacity (oxygen consumption and ATP synthesis) was measured in saponin-skinned fibers. Activities of mitochondrial respiratory chain complexes and antioxidant enzymes were measured on ventricle homogenates. Morphometric analysis of mitochondria was performed on electron micrographs. In normoxia-recovery rats, oxidative capacities of right ventricles were decreased in the presence of glutamate or palmitoyl carnitine as substrates. In contrast, oxidation of palmitoyl carnitine was maintained in the left ventricle. Enzyme activities of complexes III and IV were significantly decreased in both ventricles. These functional alterations were associated with a decrease in numerical density and an increase in size of mitochondria. Finally, in the normoxia-recovery group, the antioxidant enzyme activities (catalase and glutathione peroxidase) increased. In conclusion, alterations of mitochondrial energy metabolism induced by chronic hypoxia are not totally reversible. Reactive oxygen species could be involved and should be investigated under such conditions, since they may represent a therapeutic target.
Collapse
Affiliation(s)
- Karine Nouette-Gaulain
- Department of Anesthesiology and Intensive Care Medicine, INSERM U, Centre Hospitalier Universitaire de Bordeaux, Université Victor Segalen Bordeaux, France
| | | | | | | | | | | | | |
Collapse
|
12
|
Kosanovic D, Kojonazarov B, Luitel H, Dahal BK, Sydykov A, Cornitescu T, Janssen W, Brandes RP, Davie N, Ghofrani HA, Weissmann N, Grimminger F, Seeger W, Schermuly RT. Therapeutic efficacy of TBC3711 in monocrotaline-induced pulmonary hypertension. Respir Res 2011; 12:87. [PMID: 21699729 PMCID: PMC3141422 DOI: 10.1186/1465-9921-12-87] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Accepted: 06/23/2011] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Endothelin-1 signalling plays an important role in pathogenesis of pulmonary hypertension. Although different endothelin-A receptor antagonists are developed, a novel therapeutic option to cure the disease is still needed. This study aims to investigate the therapeutic efficacy of the selective endothelin-A receptor antagonist TBC3711 in monocrotaline-induced pulmonary hypertension in rats. METHODS Monocrotaline-injected male Sprague-Dawley rats were randomized and treated orally from day 21 to 35 either with TBC3711 (Dose: 30 mg/kg body weight/day) or placebo. Echocardiographic measurements of different hemodynamic and right-heart hypertrophy parameters were performed. After day 35, rats were sacrificed for invasive hemodynamic and right-heart hypertrophy measurements. Additionally, histologic assessment of pulmonary vascular and right-heart remodelling was performed. RESULTS The novel endothelin-A receptor antagonist TBC3711 significantly attenuated monocrotaline-induced pulmonary hypertension, as evident from improved hemodynamics and right-heart hypertrophy in comparison with placebo group. In addition, muscularization and medial wall thickness of distal pulmonary vessels were ameliorated. The histologic evaluation of the right ventricle showed a significant reduction in fibrosis and cardiomyocyte size, suggesting an improvement in right-heart remodelling. CONCLUSION The results of this study suggest that the selective endothelin-A receptor antagonist TBC3711 demonstrates therapeutic benefit in rats with established pulmonary hypertension, thus representing a useful therapeutic approach for treatment of pulmonary hypertension.
Collapse
MESH Headings
- Administration, Oral
- Animals
- Antihypertensive Agents/administration & dosage
- Antihypertensive Agents/pharmacology
- Disease Models, Animal
- Echocardiography, Doppler
- Endothelin A Receptor Antagonists
- Fibrosis
- Hemodynamics/drug effects
- Hypertension, Pulmonary/chemically induced
- Hypertension, Pulmonary/diagnostic imaging
- Hypertension, Pulmonary/drug therapy
- Hypertension, Pulmonary/metabolism
- Hypertension, Pulmonary/physiopathology
- Hypertrophy, Right Ventricular/diagnostic imaging
- Hypertrophy, Right Ventricular/drug therapy
- Hypertrophy, Right Ventricular/metabolism
- Hypertrophy, Right Ventricular/physiopathology
- Isoxazoles/administration & dosage
- Isoxazoles/pharmacology
- Male
- Monocrotaline
- Pulmonary Artery/drug effects
- Pulmonary Artery/physiopathology
- Rats
- Rats, Sprague-Dawley
- Receptor, Endothelin A/metabolism
- Sulfones/administration & dosage
- Sulfones/pharmacology
- Time Factors
- Ventricular Function, Right/drug effects
- Ventricular Remodeling/drug effects
Collapse
|
13
|
de La Roque ED, Thiaudière E, Ducret T, Marthan R, Franconi JM, Guibert C, Parzy E. Effect of chronic hypoxia on pulmonary artery blood velocity in rats as assessed by electrocardiography-triggered three-dimensional time-resolved MR angiography. NMR IN BIOMEDICINE 2011; 24:225-230. [PMID: 20945307 DOI: 10.1002/nbm.1574] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 03/30/2010] [Accepted: 05/12/2010] [Indexed: 05/30/2023]
Abstract
Pulmonary arterial hypertension (PAH) is a severe disease that leads to increased pulmonary vascular resistance and right heart failure. Noninvasive methods are needed to detect changes in the pulmonary artery circulation during PAH establishment and/or treatment. Pulmonary blood flow velocity can be evaluated by dynamic MR angiography, although the relevance of such data in the context of PAH remains to be demonstrated. A novel dynamic MR angiography technique was used in this work to measure blood flow velocity in the pulmonary arteries of the same living animals, before and after the establishment of chronic hypoxia-induced PAH. Chronic hypoxia decreased significantly the blood flow velocity (43.8 ± 4.9 vs 24.3 ± 8.7 cm/s) on electrocardiography-triggered time-resolved angiograms. In parallel, chronic hypoxia-induced PAH was confirmed from invasive measurements of the mean pulmonary arterial pressure (32.1 ± 4.8 vs 12.5 ± 2.2 mmHg) and the ratio of the right ventricle weight to the left ventricle plus septum weight (Fulton index: 0.54 ± 0.06 vs 0.27 ± 0.04). This study demonstrates the potential interest of dynamic MR angiography for the investigation of experimental models and for the evaluation of treatment efficacy.
Collapse
|
14
|
Das R, Jahr H, van Osch GJVM, Farrell E. The role of hypoxia in bone marrow-derived mesenchymal stem cells: considerations for regenerative medicine approaches. TISSUE ENGINEERING PART B-REVIEWS 2010; 16:159-68. [PMID: 19698058 DOI: 10.1089/ten.teb.2009.0296] [Citation(s) in RCA: 221] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bone marrow-derived mesenchymal stem cells (MSCs) have demonstrated potential for regenerative medicine strategies. Knowledge of the way these cells respond to their environment in in vitro culture and after implantation in vivo is crucial for successful therapy. Oxygen tension plays a pivotal role in both situations. In vivo, a hypoxic environment can lead to apoptosis, but hypoxic preconditioning of MSCs and overexpression of prosurvival genes like Akt can reduce hypoxia-induced cell death. In cell culture, hypoxia can increase proliferation rates and enhance differentiation along the different mesenchymal lineages. Hypoxia also modulates the paracrine activity of MSCs, causing upregulation of various secretable factors, among which are important angiogenic factors such as vascular endothelial growth factor and interleukin-6 (IL6). Finally, hypoxia plays an important role in mobilization and homing of MSCs, primarily by its ability to induce stromal cell-derived factor-1 expression along with its receptor CXCR4. This article reviews the current literature on the effects of hypoxia on MSCs and aims to elucidate its potential role in regenerative medicine strategies.
Collapse
Affiliation(s)
- Ruud Das
- Department of Orthopaedics, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | | | | | | |
Collapse
|
15
|
Desbuards N, Antier D, Rochefort GY, Apfeldorfer CS, Schenck E, Hanton G, Hyvelin JM. Dexfenfluramine discontinuous treatment does not worsen hypoxia-induced pulmonary vascular remodeling but activates RhoA/ROCK pathway: consequences on pulmonary hypertension. Eur J Pharmacol 2008; 602:355-63. [PMID: 19049806 DOI: 10.1016/j.ejphar.2008.11.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2008] [Revised: 10/23/2008] [Accepted: 11/10/2008] [Indexed: 11/17/2022]
Abstract
The anorectic drug, dexfenfluramine has been associated with an increase in the relative risk of developing pulmonary hypertension. 5-hydroxytryptamine (5-HT) is a mitogen for smooth muscle cell, an effect that relies on 5-HT transporter expression and which has been proposed to explain pulmonary side effect of dexfenfluramine, and more particularly its effect on vascular remodeling. However recent data supported a major role of pulmonary artery vasoconstriction through the RhoA/Rho-kinase pathway. We questioned whether or not anorectic treatment aggravates pulmonary hypertension through vascular remodeling and if RhoA/Rho-kinase (ROCK) was potentially involved. In rats exposed to hypoxia, concomitant dexfenfluramine treatment (5 mg/kg/day, i.v.) for 4 weeks had no effect on pulmonary hypertension development. When exposure to 2 weeks of chronic hypoxia followed discontinuation of dexfenfluramine treatment (dexfenfluramine-hypoxic rats), echocardiographic parameters of pulmonary artery flow and right ventricle were further altered (P<0.05) as well as right ventricle systolic pressure was further increased (P<0.001) when compared to hypoxic rats treated with vehicle (hypoxic rats). However, the total number of muscularized distal pulmonary arteries artery was similar in dexfenfluramine-hypoxic vs. hypoxic rats (P>0.05). Western blot, RT-PCR and immunofluorescence analysis revealed a greater expression of 5-HT transporter and ROCK, as well as a greater activation of RhoA in dexfenfluramine-hypoxic rats compared to hypoxic rats. These data show that increased 5-HT transporter expression that follows dexfenfluramine discontinuation is not associated to a greater vascular remodeling despite worsening the development of pulmonary hypertension. Furthermore dexfenfluramine discontinuation promotes a greater RhoA/ROCK pathway activation. This pathway, involved in many cardiovascular diseases, might explain the cardiac and pulmonary toxicity of serotoninergic agonists.
Collapse
Affiliation(s)
- Nicolas Desbuards
- Laboratoire de Physiopathologie de la Paroi Artérielle, LABPART EA3852, IFR 135, Université François Rabelais, Tours Cedex 1, France
| | | | | | | | | | | | | |
Collapse
|
16
|
Akhavein F, St-Michel EJ, Seifert E, Rohlicek CV. Decreased left ventricular function, myocarditis, and coronary arteriolar medial thickening following monocrotaline administration in adult rats. J Appl Physiol (1985) 2007; 103:287-95. [PMID: 17412785 DOI: 10.1152/japplphysiol.01509.2005] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Decreased right as well as left ventricular function can be associated with pulmonary hypertension (PH). Numerous investigations have examined cardiac function following induction of pulmonary hypertension with monocrotaline (MCT) assuming that MCT has no direct cardiac effect. We tested this assumption by examining left ventricular function and histology of isolated and perfused hearts from MCT-treated rats. Experiments were performed on 50 male Sprague-Dawley rats [348 +/- 6 g (SD)]. Thirty-seven rats received MCT (50 mg/kg sc; MCT group) while the remainder did not (Control group). Three weeks later, pulmonary artery pressure was assessed echocardiographically in 20 MCT and 8 Control rats. The hearts were then excised and perfused in the constant pressure Langendorff mode to determine peak left ventricular pressure (LVP), the peak instantaneous rate of pressure increase (+dP/dtmax) and decrease (-dP/dtmax), as well as the rate pressure product (RPP). Histological sections were subsequently examined. Pulmonary artery pressure was higher in the MCT-treated group compared with the Control group [12.9 +/- 6 vs. 51 +/- 35.3 mmHg (P < 0.01)]. Left ventricular systolic function and diastolic relaxation were decreased in the MCT group compared with the Control group (+dP/dtmax 4,178 +/- 388 vs. 2,801 +/- 503 mmHg/s, LVP 115 +/- 11 vs. 83 +/- 14 mmHg, RPP 33,688 +/- 1,910 vs. 23,541 +/- 3,858 beats x min(-1) x mmHg(-1), -dP/dtmax -3,036 +/- 247 vs. -2,091 +/- 389 mmHg/s; P < 0.0001). The impairment of cardiac function was associated with myocarditis and coronary arteriolar medial thickening. Similarly depressed ventricular function and inflammatory infiltration was seen in 12 rats 7 days after MCT administration. Our findings appear unrelated to the degree of PH and indicate a direct cardiotoxic effect of MCT.
Collapse
Affiliation(s)
- F Akhavein
- Department of Pediatrics, McGill University and Division of Cardiology, Montreal Children's Hospital, McGill University Health Centre, Montreal, Quebec, Canada
| | | | | | | |
Collapse
|
17
|
Characterization of a rat model of right-sided heart failure induced by pulmonary trunk banding. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.jeas.2006.10.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
18
|
Rochefort GY, Lemaire MC, Eder V, Hanton G, Hyvelin JM, Bonnet P, Antier D. Dexfenfluramine does not worsen but moderates progression of chronic hypoxia-induced pulmonary hypertension. Eur J Pharmacol 2006; 550:149-54. [PMID: 17026993 DOI: 10.1016/j.ejphar.2006.08.050] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Revised: 08/22/2006] [Accepted: 08/28/2006] [Indexed: 10/24/2022]
Abstract
This study shows for the first time, that dexfenfluramine, a 5-HT(2) receptor agonist, attenuates the development of chronic hypoxia-induced pulmonary hypertension. Chronic exposure to hypoxia, 4 weeks, induced hypoxic pulmonary hypertension in adult rat as haemodynamic and cardiac measurements showed significant modifications in right ventricle parameters (free wall right ventricle thickness; pulmonary acceleration time and velocity time integral) in chronic hypoxic control when compared to normoxic control animals. We observed that free wall right ventricle thickness and pulmonary velocity time integral were significantly less in chronic hypoxic rats treated with dexfenfluramine when compared to chronic hypoxic control rats. Similarly, rats exposed to chronic hypoxia exhibited an increase in both right ventricle pressure and weight by comparison to normoxic control animals but those variations were significantly diminished in dexfenfluramine-treated rats, indicating the moderating influence exerted by dexfenfluramine on chronic hypoxia-induced pulmonary hypertension and cardiac alterations. Thus, we report here the ability of dexfenfluramine to limit chronic hypoxia-induced pulmonary hypertension, emphasizing the importance of the time after the dexfenfluramine treatment discontinuation to assess the influence of this 5-HT receptor agonist on the development of chronic hypoxia-induced pulmonary hypertension.
Collapse
Affiliation(s)
- Gaël Y Rochefort
- LABPART - EA 3852 - IFR135 - Université François Rabelais, 10 Bd Tonnellé BP 3223, 37032 Tours Cedex 1, France
| | | | | | | | | | | | | |
Collapse
|
19
|
Rochefort GY, Delorme B, Lopez A, Hérault O, Bonnet P, Charbord P, Eder V, Domenech J. Multipotential mesenchymal stem cells are mobilized into peripheral blood by hypoxia. Stem Cells 2006; 24:2202-8. [PMID: 16778152 DOI: 10.1634/stemcells.2006-0164] [Citation(s) in RCA: 225] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
MSCs constitute a population of multipotential cells giving rise to adipocytes, osteoblasts, chondrocytes, and vascular-smooth muscle-like hematopoietic supportive stromal cells. It remains unclear whether MSCs can be isolated from adult peripheral blood under stationary conditions and whether they can be mobilized in a way similar to hematopoietic stem cells. In this report, we show that MSCs are regularly observed in the circulating blood of rats and that the circulating MSC pool is consistently and dramatically increased (by almost 15-fold) when animals are exposed to chronic hypoxia. The immunophenotype and the adipocytic, osteoblastic, and chondrocytic differentiation potential of circulating MSCs were similar to those of bone marrow MSCs. Hypoxia-induced mobilization appears to be specific for MSCs since total circulating hematopoietic progenitor cells were not significantly increased. Our data provide an in vivo model amenable to analysis of MSC-mobilizing factors.
Collapse
Affiliation(s)
- Gaël Y Rochefort
- Upres-Ea3852, Université François Rabelais de Tours and Chru de Tours, Tours, France
| | | | | | | | | | | | | | | |
Collapse
|
20
|
Lederlin M, Thiaudiere E, Laurent F, Franconi JM, Parzy E. In vivo MR imaging of pulmonary arteries of normal and experimental emboli in small animals. J Magn Reson Imaging 2006; 24:1298-302. [PMID: 17083119 DOI: 10.1002/jmri.20780] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To demonstrate the feasibility of pulmonary MRA in living rodents. MATERIALS AND METHODS A three-dimensional (3D) gradient echo sequence was adapted to perform a time-of-flight (TOF) angiography of rat lung. Angiogram with a spatial resolution of 195 x 228 x 228 microm(3) was acquired in around 33 minutes. The method was then applied in animals before and after pulmonary embolism (PE) induction. Section of the proximal right pulmonary artery was measured and compared between the two populations. RESULTS Good quality images were obtained with a contrast-to-noise ratio (CNR) of 9 +/- 3 in the proximal part of the pulmonary artery. Cross-section areas of the right main artery are statistically different before (3.45 +/- 0.69 mm(2)) and after induction of PE (4.3 +/- 0.86 mm(2)). CONCLUSION This noninvasive tool permits angiogram acquisition at around 200 microm spatial resolution and objective distinction between healthy and embolized arteries.
Collapse
Affiliation(s)
- Mathieu Lederlin
- Resonance Magnetique des Systemes Biologiques (RMSB) Unite Mixte Recherche (UMR)5536, Bordeaux, France
| | | | | | | | | |
Collapse
|
21
|
Rochefort GY, Vaudin P, Bonnet N, Pages JC, Domenech J, Charbord P, Eder V. Influence of hypoxia on the domiciliation of mesenchymal stem cells after infusion into rats: possibilities of targeting pulmonary artery remodeling via cells therapies? Respir Res 2005; 6:125. [PMID: 16253136 PMCID: PMC1291404 DOI: 10.1186/1465-9921-6-125] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2004] [Accepted: 10/27/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Bone marrow (BM) cells are promising tools for vascular therapies. Here, we focused on the possibility of targeting the hypoxia-induced pulmonary artery hypertension remodeling with systemic delivery of BM-derived mesenchymal stem cells (MSCs) into non-irradiated rats. METHODS Six-week-old Wistar rats were exposed to 3-week chronic hypoxia leading to pulmonary artery wall remodeling. Domiciliation of adhesive BM-derived CD45- CD73+ CD90+ MSCs was first studied after a single intravenous infusion of Indium-111-labeled MSCs followed by whole body scintigraphies and autoradiographies of different harvested organs. In a second set of experiments, enhanced-GFP labeling allowed to observe distribution at later times using sequential infusions during the 3-week hypoxia exposure. RESULTS A 30% pulmonary retention was observed by scintigraphies and no differences were observed in the global repartition between hypoxic and control groups. Intrapulmonary radioactivity repartition was homogenous in both groups, as shown by autoradiographies. BM-derived GFP-labeled MSCs were observed with a global repartition in liver, in spleen, in lung parenchyma and rarely in the adventitial layer of remodeled vessels. Furthermore this global repartition was not modified by hypoxia. Interestingly, these cells displayed in vivo bone marrow homing, proving a preservation of their viability and function. Bone marrow homing of GFP-labeled MSCs was increased in the hypoxic group. CONCLUSION Adhesive BM-derived CD45- CD73+ CD90+ MSCs are not integrated in the pulmonary arteries remodeled media after repeated intravenous infusions in contrast to previously described in systemic vascular remodeling or with endothelial progenitor cells infusions.
Collapse
Affiliation(s)
- Gaël Y Rochefort
- LABPART-EA3852, IFR135, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
| | - Pascal Vaudin
- INSERM ESPRI-EA3588, IFR135, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
- Virus, pseudo-virus: morphogenése et antigénicité, EA3856, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
| | - Nicolas Bonnet
- Architecture du Tissu Osseux – Exercice Physique, EA 3895, Université d'Orléans- BP6749, 45067 Orléans cedex 2 France
| | - Jean-Christophe Pages
- Virus, pseudo-virus: morphogenése et antigénicité, EA3856, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
| | - Jorge Domenech
- INSERM ESPRI-EA3588, IFR135, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
| | - Pierre Charbord
- INSERM ESPRI-EA3588, IFR135, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
| | - Véronique Eder
- LABPART-EA3852, IFR135, Université François Rabelais, faculté de Médecine, 10 boulevard Tonnellé 370032 TOURS France
| |
Collapse
|
22
|
Boissiere J, Gautier M, Machet MC, Hanton G, Bonnet P, Eder V. Doppler tissue imaging in assessment of pulmonary hypertension-induced right ventricle dysfunction. Am J Physiol Heart Circ Physiol 2005; 289:H2450-5. [PMID: 16055521 DOI: 10.1152/ajpheart.00524.2005] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We aimed to assess the accuracy of Doppler tissue imaging (DTI) in detecting right ventricle (RV) dysfunction and electromechanical coupling alteration following pulmonary hypertension (PHT) in rat. PHT was induced by chronic hypoxia exposure (hypoxic PHT) or monocrotaline treatment (monocrotaline PHT). In both PHT models, we observed transparietal RV pressure increase and remodeling, including hypertrophy and dilation. Conventional echocardiography provided evidence for pulmonary outflow impairment with midsystolic notch and acceleration time decrease in PHT groups (21.7 +/- 1.6 and 13.2 +/- 2.9 ms in hypoxic and monocrotaline PHT groups vs. 28.1 +/- 1.0 ms in control). RV shortening fraction was decreased in the monocrotaline PHT group compared with the hypoxic PHT and control groups. Combining conventional Doppler and DTI was more helpful to detect RV diastolic dysfunction in the monocrotaline PHT group (E/Ea ratio = 17.0 +/- 1.4) compared with the hypoxic PHT and control groups (11.5 +/- 0.7 and 10.2 +/- 0.4, respectively). Tei index measured using DTI highlighted global RV dysfunction in the monocrotaline PHT group (1.36 +/- 0.24 vs. 0.92 +/- 0.05 and 0.86 +/- 0.05 in the hypoxic PHT and control groups, respectively). Q-Sm time measured from the onset of Q wave to the onset of DTI Sm wave was increased in both PHT groups. PHT-induced electromechanical coupling alteration was confirmed by in vitro activation-contraction delay measurements on isolated RV papillary muscle, and both Q-Sm time and activation-contraction delay were correlated with PHT severity. We demonstrated that Q-Sm time measured in DTI was an easily and convenient index to detect early RV electromechanical coupling alteration in both moderate and severe PHT.
Collapse
Affiliation(s)
- Julien Boissiere
- Faculté de Médecine, Laboratoire de Physiopathologie de la Paroi Artérielle (LABPART 10 Boulevard Tonnellé, BP 3223, 37032 Tours Cedex 1, France
| | | | | | | | | | | |
Collapse
|
23
|
Ladha F, Bonnet S, Eaton F, Hashimoto K, Korbutt G, Thébaud B. Sildenafil improves alveolar growth and pulmonary hypertension in hyperoxia-induced lung injury. Am J Respir Crit Care Med 2005; 172:750-6. [PMID: 15947285 DOI: 10.1164/rccm.200503-510oc] [Citation(s) in RCA: 143] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Bronchopulmonary dysplasia (BPD), the chronic lung disease of preterm infants, and pulmonary emphysema, both significant global health problems, are characterized by an arrest in alveolar growth/loss of alveoli structures. Mechanisms that inhibit distal lung growth are poorly understood, but recent studies suggest that impaired vascular endothelial growth factor signaling and reduced nitric oxide (NO) production decreases alveolar and vessel growth in the developing lung, features observed in experimental oxygen-induced BPD. NO exerts its biological activity by stimulating guanosine 3',5'-cyclic monophosphate (cGMP) production. OBJECTIVES Because cGMP is inactivated by phosphodiesterase (PDE) enzymes, we hypothesized that the cGMP-specific PDE5 inhibitor sildenafil would promote angiogenesis and attenuate oxygen-induced lung injury in newborn rats. METHODS, MEASUREMENTS, AND MAIN RESULTS: In vitro, sildenafil (10(-4) M) increased endothelial capillary network formation of human pulmonary endothelial cells exposed to hyperoxia. In vivo, rat pups were randomly exposed from birth to normoxia, hyperoxia (95% O(2), BPD model), and hyperoxia+sildenafil (100 mg/kg/day subcutaneously). Rat pups exposed to hyperoxia showed fewer and enlarged air spaces as well as decreased capillary density, mimicking pathologic features seen in human BPD. These structural anomalies were associated with echographic (decreased pulmonary acceleration time) and structural (right ventricular hypertrophy and increased medial wall thickness) signs of pulmonary hypertension. Sildenafil preserved alveolar growth and lung angiogenesis, and decreased pulmonary vascular resistance, right ventricular hypertrophy and medial wall thickness. CONCLUSIONS Our findings suggest a role for the NO/cGMP pathway during alveolar development. Sildenafil may have therapeutic potential in diseases associated with impaired alveolar structures.
Collapse
Affiliation(s)
- Faruqa Ladha
- Department of Pediatrics, Division of Neonatology, Surgical-Medical Research Institute, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | | | | |
Collapse
|