Cardiac modulations of ANG II receptor expression in rats with hypoxic pulmonary hypertension

2002 ◽  
Vol 283 (2) ◽  
pp. H733-H740 ◽  
Author(s):  
Christophe Adamy ◽  
Patricia Oliviero ◽  
Saadia Eddahibi ◽  
Lydie Rappaport ◽  
Jane-Lise Samuel ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Chronic Hypoxia ◽  
Renin Angiotensin System ◽  
Left Ventricular ◽  
Receptor Expression ◽  
Mrna Levels ◽  
Hypoxic Pulmonary Hypertension ◽  
Cardiac Ventricles ◽  
The Right

Right ventricular myocardial hypertrophy during hypoxic pulmonary hypertension is associated with local renin-angiotensin system activation. The expression of angiotensin II type 1 (AT1) and type 2 (AT2) receptors in this setting has never been investigated. We have therefore examined the chronic hypoxia pattern of AT1 and AT2expression in the right and left cardiac ventricles, using in situ binding and RT-PCR assays. Hypoxia produced right, but not left, ventricular hypertrophy after 7, 14, and 21 days, respectively. Hypoxia for 2 days was associated in each ventricle with a simultaneous and transient increase ( P < 0.05) in AT1 binding and AT1 mRNA levels in the absence of any significant change in AT2 expression level. Only after 14 days of hypoxia, AT2 binding increased ( P < 0.05) in the two ventricles, concomitantly with a right ventricular decrease ( P < 0.05) in AT2 mRNA. Along these data, AT1 and AT2 binding remained unchanged in both the left and hypertrophied right ventricles from rats treated with monocrotaline for 30 days. These results indicate that chronic hypoxia induces modulations of AT1 and AT2 receptors in both cardiac ventricles probably through direct and indirect mechanisms, respectively, which modulations may participate in myogenic (at the level of smooth or striated myocytes) rather than in the growth response of the heart to hypoxia.

C-type natriuretic peptide expression and pulmonary vasodilation in hypoxia-adapted rats

1998 ◽  
Vol 275 (4) ◽  
pp. L645-L652 ◽  
Author(s):  
James R. Klinger ◽  
Farjaad M. Siddiq ◽  
Richard A. Swift ◽  
Cynthia Jackson ◽  
Linda Pietras ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricle ◽  
Natriuretic Peptide ◽  
Right Atrium ◽  
Chronic Hypoxia ◽  
Right Atrial ◽  
Mrna Levels ◽  
Hypoxic Pulmonary Hypertension ◽  
Pulmonary Arterial ◽  
The Right

Atrial and brain natriuretic peptides (ANP and BNP, respectively) are potent pulmonary vasodilators that are upregulated in hypoxia-adapted rats and may protect against hypoxic pulmonary hypertension. To test the hypothesis that C-type natriuretic peptide (CNP) also modulates pulmonary vascular responses to hypoxia, we compared the vasodilator effect of CNP with that of ANP on pulmonary arterial rings, thoracic aortic rings, and isolated perfused lungs obtained from normoxic and hypoxia-adapted rats. We also measured CNP and ANP levels in heart, lung, brain, and plasma in normoxic and hypoxia-adapted rats. Steady-state CNP mRNA levels were quantified in the same organs by relative RT-PCR. CNP was a less potent vasodilator than ANP in preconstricted thoracic aortic and pulmonary arterial rings and in isolated lungs from normoxic and hypoxia-adapted rats. Chronic hypoxia increased plasma CNP (15 ± 2 vs. 6 ± 1 pg/ml; P < 0.05) and decreased CNP in the right atrium (35 ± 14 vs. 65 ± 17 pg/mg protein; P < 0.05) and in the lung (3 ± 1 vs. 14 ± 3 pg/mg protein; P < 0.05) but had no effect on CNP in brain or right ventricle. Chronic hypoxia increased ANP levels fivefold in the right ventricle (49 ± 5 vs. 11 ± 2 pg/mg protein; P < 0.05) but had no effect on ANP in lung or brain. There was a trend toward decreased ANP levels in the right atrium (2,009 ± 323 vs. 2,934 ± 397 pg/mg protein; P = not significant). No differences in CNP transcript levels were observed between the two groups of rats except that the right atrial CNP mRNA levels were lower in hypoxia-adapted rats. We conclude that CNP is a less potent pulmonary vasodilator than ANP in normoxic and hypoxia-adapted rats and that hypoxia raises circulating CNP levels without increasing cardiopulmonary CNP expression. These findings suggest that CNP may be less important than ANP or BNP in protecting against hypoxic pulmonary hypertension in rats.

Insulin-like growth factor-I gene expression is increased in the right ventricular hypertrophy induced by chronic hypoxia in the rat

1993 ◽  
Vol 10 (1) ◽  
pp. 99-102 ◽  
Author(s):  
D L Russell-Jones ◽  
R M Leach ◽  
J P T Ward ◽  
C R Thomas
Keyword(s):  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Northern Blot Analysis ◽  
Chronic Hypoxia ◽  
Left Ventricular ◽  
Mrna Levels ◽  
Factor I ◽  
Igf I ◽  
The Right ◽  
Air Control

ABSTRACT Rats were maintained in chambers and breathed air (control, n=8) or an atmosphere containing 10% oxygen (hypoxic, n=10) for 35 days. On completion of the experiment the hypoxic animals weighed less than the controls (hypoxic, 290 ± 11.7g; control, 339 ± 19.2g; means ± S.E.M., p<0.05). No differences in the left ventricular weights were found between groups but the right ventricular weights were greater in the hypoxic rats (hypoxic, 0.39 ± 0.02g; control, 0.27 ± 0.08g; p<0.01). The amount of mRNA for IGF-I in the ventricles was quantified by Northern blot analysis. There was no difference between groups in IGF-I mRNA levels in the left ventricles (hypoxic, 1.07 ± 0.41 absorbance units (AU); control, 0.73 ± 0.33 AU). In the right ventricles, IGF-I mRNA was greater in hypoxic than in control rats (hypoxic, 2.37 ± 0.75 AU; control, 0.64 ± 0.11 AU; p<0.05). This study demonstrates that expression of IGF-I mRNA is increased in the hypertrophied right ventricle of hypoxic rats; IGF-I may play a central role in the initiation and maintenance of this process.

Norepinephrine and dobutamine improve cardiac index equally by supporting opposite sides of the heart in an experimental model of chronic pulmonary hypertension

2021 ◽  
Author(s):  
Janus Adler Hyldebrandt ◽  
Nikolaj Bøgh ◽  
Camilla Omann Christensen ◽  
Peter Agger
Keyword(s):  
Pulmonary Hypertension ◽  
Cardiac Index ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
Left Ventricular ◽  
Ventricular Contractility ◽  
End Diastolic Volume ◽  
Chronic Pulmonary Hypertension ◽  
Blood Pressures ◽  
The Right

Abstract Background: Pulmonary hypertension is a significant risk factor in patients undergoing surgery. The combined effects of general anaesthesia and positive pressure ventilation can aggravate this condition and cause increased pulmonary blood pressures, reduced systemic blood pressures and ventricular contractility. Although perioperative use of inotropic support or vasopressors is almost mandatory for these patients, preference is disputed. In this study, we investigated the effects of norepinephrine and dobutamine and their ability to improve the arterio-ventricular relationship and haemodynamics in pigs suffering from chronic pulmonary hypertension.Method: Pulmonary hypertension was induced in five pigs by banding the pulmonary artery at 2–3 weeks of age. Six pigs served as controls. After 16 weeks of pulmonary artery banding, the animals were re-examined under general anaesthesia using biventricular conductance catheters and a pulmonary artery catheter. After baseline measurements, the animals were exposed to both norepinephrine and dobutamine infusions in incremental doses, with a stabilizing period in between the infusions. The hypothesis of differences between norepinephrine and dobutamine with incremental doses was tested using repeated two-way ANOVA and Bonferroni multiple comparisons post-test. Results: At baseline, pulmonary artery banded animals had increased right ventricular pressure (+39%, p=0.04), lower cardiac index (-23% p=0.04), lower systolic blood pressure (-13%, p=0.02) and reduced left ventricular end-diastolic volume (-33%, p=0.02). When incremental doses of norepinephrine and dobutamine were administered, the right ventricular arterio-ventricular coupling was improved only by dobutamine (p<0.05). Norepinephrine increased both left ventricular end-diastolic volume and left ventricular contractility to a greater extent (p<0.05) in pulmonary artery banded animals. While the cardiac index was improved equally by norepinephrine and dobutamine treatments in pulmonary artery banded animals, norepinephrine had a significantly greater effect on mean arterial pressure (p<0.05) and diastolic arterial pressure (p<0.05).Conclusion: While norepinephrine and dobutamine improved cardiac index equally, it was obtained in different manners. Dobutamine significantly improved the right ventricular function and the arterio-ventricular coupling. Norepinephrine increased systemic resistance, thereby improving arterial pressures and left ventricular systolic function by maintaining left ventricular end-diastolic volume.

Neutral endopeptidase inhibition attenuates development of hypoxic pulmonary hypertension in rats

1993 ◽  
Vol 75 (4) ◽  
pp. 1615-1623 ◽  
Author(s):  
J. R. Klinger ◽  
R. D. Petit ◽  
R. R. Warburton ◽  
D. S. Wrenn ◽  
F. Arnal ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Pulmonary Arteries ◽  
Systolic Pressure ◽  
Weight Ratio ◽  
Neutral Endopeptidase ◽  
Mrna Levels ◽  
Hypoxic Pulmonary Hypertension ◽  
Ventricular Systolic Pressure ◽  
Nep Inhibition

Neutral endopeptidase (NEP) inhibition is thought to blunt hypoxic pulmonary hypertension by reducing atrial natriuretic peptide (ANP) metabolism, but this hypothesis has not been confirmed. We measured NEP activity, guanosine 3',5'-cyclic monophosphate (cGMP) production, plasma ANP levels, and cardiac ANP synthesis in rats given an orally active NEP inhibitor (SCH-34826) during 3 wk of hypoxia. Under normoxic conditions, SCH-34826 had no effect on plasma ANP levels but reduced pulmonary and renal NEP activity by 50% and increased urinary cGMP levels (60 +/- 6 vs. 22 +/- 4 pg/mg creatinine; P < 0.05). Under hypoxic conditions, SCH-34826-treated rats had lower plasma ANP levels (1,259 +/- 361 vs. 2,101 +/- 278 pg/ml; P < 0.05), lower right ventricular systolic pressure (53 +/- 5 vs. 73 +/- 2 mmHg; P < 0.05), lower right ventricle weight-to-left ventricle+septum weight ratio (0.47 +/- 0.04 vs. 0.53 +/- 0.03; P < 0.05), and less muscularization and percent medial wall thickness of peripheral pulmonary arteries (22 +/- 5 vs. 45 +/- 8% and 17 +/- 1 vs. 25 +/- 1%, respectively; P < 0.05 for all values) than did rats treated with vehicle alone. These values were not affected by SCH-34826 under normoxic conditions. SCH-34826 decreased right ventricular ANP tissue levels in hypoxic rats (27 +/- 10 vs. 8 +/- 1 ng/mg protein; P < 0.05) but did not affect steady-state ANP mRNA levels. We conclude that NEP inhibition blunts pulmonary hypertension without increasing plasma ANP levels.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Genetic Analysis of Right Heart Structure and Function in 40,000 People

2021 ◽  
Author(s):  
James P. Pirruccello ◽  
Paolo Di Achille ◽  
Victor Nauffal ◽  
Mahan Nekoui ◽  
Samuel N. Friedman ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Deep Learning ◽  
Right Ventricular ◽  
Congenital Heart ◽  
Left Ventricular ◽  
Structure And Function ◽  
Right Heart ◽  
Heart Chamber ◽  
The Right ◽  
And Function

The heart evolved hundreds of millions of years ago. During mammalian evolution, the cardiovascular system developed with complete separation between pulmonary and systemic circulations incorporated into a single pump with chambers dedicated to each circulation. A lower pressure right heart chamber supplies deoxygenated blood to the lungs, while a high pressure left heart chamber supplies oxygenated blood to the rest of the body. Due to the complexity of morphogenic cardiac looping and septation required to form these two chambers, congenital heart diseases often involve maldevelopment of the evolutionarily recent right heart chamber. Additionally, some diseases predominantly affect structures of the right heart, including arrhythmogenic right ventricular cardiomyopathy (ARVC) and pulmonary hypertension. To gain insight into right heart structure and function, we fine-tuned deep learning models to recognize the right atrium, the right ventricle, and the pulmonary artery, and then used those models to measure right heart structures in over 40,000 individuals from the UK Biobank with magnetic resonance imaging. We found associations between these measurements and clinical disease including pulmonary hypertension and dilated cardiomyopathy. We then conducted genome-wide association studies, identifying 104 distinct loci associated with at least one right heart measurement. Several of these loci were found near genes previously linked with congenital heart disease, such as NKX2-5, TBX3, WNT9B, and GATA4. We also observed interesting commonalities and differences in association patterns at genetic loci linked with both right and left ventricular measurements. Finally, we found that a polygenic predictor of right ventricular end systolic volume was associated with incident dilated cardiomyopathy (HR 1.28 per standard deviation; P = 2.4E-10), and remained a significant predictor of disease even after accounting for a left ventricular polygenic score. Harnessing deep learning to perform large-scale cardiac phenotyping, our results yield insights into the genetic and clinical determinants of right heart structure and function.

P5370Pulmonary pressure overload stimulates cardiac stem or progenitor cell-derived cardiac regeneration in the right ventricular area

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
M Kanda ◽  
T Nagai ◽  
N Kondou ◽  
K Tateno ◽  
M Hirose ◽  
...  
Keyword(s):  
Heart Failure ◽  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Progenitor Cell ◽  
Pressure Overload ◽  
Right Heart Failure ◽  
Left Ventricular ◽  
Free Wall ◽  
Right Heart ◽  
The Right

Abstract Introduction and purpose The number of patients with right heart failure due to pulmonary hypertension has been increasing. Although several drugs have reportedly improved pulmonary hypertension, no treatments have been established for decompensated right heart failure. The heart has an innate ability to regenerate, and cardiac stem or progenitor cells (e.g., side population [SP] cells) have been reported to contribute to the regeneration process. However, their contribution to right ventricular pressure overload has not been clarified. Here, this regeneration process was evaluated using a genetic fate-mapping model. Methods and results We used Cre-LacZ mice, in which more than 99.9% of the cardiomyocytes in the left ventricular field were positive for 5-bromo-4-chloro-3-indolyl-β-D-galactoside (X-gal) staining immediately after tamoxifen injection. Then, we performed either a pulmonary binding (PAB) or sham operation on the main pulmonary tract. In the PAB-treated mice, the right ventricular cavity was significantly enlarged (right-to-left ventricular [RV/LV] ratio, 0.24±0.04 in the sham group and 0.68±0.04 in the PAB group). Increased peak flow velocity in the PAB group (1021±80 vs 1351±62 mm/sec) was confirmed by echocardiography. One month after the PAB, the PAB-treated mice had more X-gal-negative (newly generated) cells than the sham mice (94.8±34.2 cells/mm2 vs 23.1±10.5 cells/mm2; p<0.01). The regeneration was biased in the RV free wall (RV free wall, 225.5±198.7 cells/mm2; septal area, 88.9±56.5/mm2; LV lateral area, 46.8±22.0/mm2; p<0.05). To examine the direct effects of PAB on the cardiac progenitor cells, bromodeoxyuridine was administered to the mice daily until 1 week after the PAB operation. Then, the hearts were isolated and SP cells were harvested. The SP cell population increased from 0.65±0.23% in the sham mice to 1.87% ± 1.18% in the PAB-treated mice. Immunostaining analysis revealed a significant increase in the number of BrdU-positive SP cells, from 11.6±2.0% to 44.0±18%, therefore showing SP cell proliferation. Conclusions Pulmonary pressure overload stimulated cardiac stem or progenitor cell-derived regeneration with a RV bias, and SP cell proliferation may partially contribute to this process. Acknowledgement/Funding JSPS KAKENHI Grant Number JP 17K17636, GSK Japan Research Grant 2016

p53 Gene deficiency promotes hypoxia-induced pulmonary hypertension and vascular remodeling in mice

2011 ◽  
Vol 300 (5) ◽  
pp. L753-L761 ◽  
Author(s):  
Shiro Mizuno ◽  
Herman J. Bogaard ◽  
Donatas Kraskauskas ◽  
Aysar Alhussaini ◽  
Jose Gomez-Arroyo ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Left Ventricle ◽  
Right Ventricular ◽  
Vascular Remodeling ◽  
Ventricular Hypertrophy ◽  
Chronic Hypoxia ◽  
Hypoxic Exposure ◽  
Arterial Remodeling ◽  
Pulmonary Arterial ◽  
The Right

Chronic hypoxia induces pulmonary arterial remodeling, resulting in pulmonary hypertension and right ventricular hypertrophy. Hypoxia has been implicated as a physiological stimulus for p53 induction and hypoxia-inducible factor-1α (HIF-1α). However, the subcellular interactions between hypoxic exposure and expression of p53 and HIF-1α remain unclear. To examine the role of p53 and HIF-1α expression on hypoxia-induced pulmonary arterial remodeling, wild-type (WT) and p53 knockout (p53KO) mice were exposed to either normoxia or hypoxia for 8 wk. Following chronic hypoxia, both genotypes demonstrated elevated right ventricular pressures, right ventricular hypertrophy as measured by the ratio of the right ventricle to the left ventricle plus septum weights, and vascular remodeling. However, the right ventricular systolic pressures, the ratio of the right ventricle to the left ventricle plus septum weights, and the medial wall thickness of small vessels were significantly greater in the p53KO mice than in the WT mice. The p53KO mice had lower levels of p21 and miR34a expression, and higher levels of HIF-1α, VEGF, and PDGF expression than WT mice following chronic hypoxic exposure. This was associated with a higher proliferating cell nuclear antigen expression of pulmonary artery in p53KO mice. We conclude that p53 plays a critical role in the mitigation of hypoxia-induced small pulmonary arterial remodeling. By interacting with p21 and HIF-1α, p53 may suppress hypoxic pulmonary arterial remodeling and pulmonary arterial smooth muscle cell proliferation under hypoxia.

Mice deficient in galectin-1 exhibit attenuated physiological responses to chronic hypoxia-induced pulmonary hypertension

2007 ◽  
Vol 292 (1) ◽  
pp. L154-L164 ◽  
Author(s):  
D. Case ◽  
D. Irwin ◽  
C. Ivester ◽  
J. Harral ◽  
K. Morris ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Chronic Hypoxia ◽  
Acute Hypoxia ◽  
Left Ventricular ◽  
Wild Type ◽  
Ph Response ◽  
Subtractive Library

Pulmonary hypertension (PH) is characterized by sustained vasoconstriction, with subsequent extracellular matrix (ECM) production and smooth muscle cell (SMC) proliferation. Changes in the ECM can modulate vasoreactivity and SMC contraction. Galectin-1 (Gal-1) is a hypoxia-inducible β-galactoside-binding lectin produced by vascular, interstitial, epithelial, and immune cells. Gal-1 regulates SMC differentiation, proliferation, and apoptosis via interactions with the ECM, as well as immune system function, and, therefore, likely plays a role in the pathogenesis of PH. We investigated the effects of Gal-1 during hypoxic PH by quantifying 1) Gal-1 expression in response to hypoxia in vitro and in vivo and 2) the effect of Gal-1 gene deletion on the magnitude of the PH response to chronic hypoxia in vivo. By constructing and screening a subtractive library, we found that acute hypoxia increases expression of Gal-1 mRNA in isolated pulmonary mesenchymal cells. In wild-type (WT) mice, Gal-1 immunoreactivity increased after 6 wk of hypoxia. Increased expression of Gal-1 protein was confirmed by quantitative Western analysis. Gal-1 knockout (Gal-1−/−) mice showed a decreased PH response, as measured by right ventricular pressure and the ratio of right ventricular to left ventricular + septum wet weight compared with their WT counterparts. However, the number and degree of muscularized vessels increased similarly in WT and Gal-1−/− mice. In response to chronic hypoxia, the decrease in factor 8-positive microvessel density was similar in both groups. Vasoreactivity of WT and Gal-1−/− mice was tested in vivo and with use of isolated perfused lungs exposed to acute hypoxia. Acute hypoxia caused a significant increase in RV pressure in wild-type and Gal-1−/− mice; however, the response of the Gal-1−/− mice was greater. These results suggest that Gal-1 influences the contractile response to hypoxia and subsequent remodeling during hypoxia-induced PH, which influences disease progression.

P885 Pulmonary artery stent implantation in an adult with chronic thromboembolic pulmonary stenosis

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
E A Khalifa ◽  
S Helmy ◽  
F Elallus ◽  
S F Mohamed ◽  
M Alkuwari
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Right Ventricular ◽  
Stent Implantation ◽  
Pulmonary Valve ◽  
Main Pulmonary Artery ◽  
Left Ventricular ◽  
Artery Stenosis ◽  
Pulmonary Artery Stenosis ◽  
The Right

Abstract Introduction Pulmonary artery stenosis presenting in adults is rare. Chronic thromboembolic pulmonary hypertension (CTEPH) is by far the most common cause of pulmonary artery stenosis. Stenosis in these patients are not caused by an abnormality of the arterial wall itself, but by intraluminal narrowing as a result of the only partially resolved and organized thromboembolism. In contrast to paediatric patients, in adults with pulmonary artery stenosis, pulmonary stenting is not routinely performed. Case report A 51-year male, smoker, diabetic, hypertensive, and with chronic kidney disease. He was diagnosed two years earlier with bilateral multiple pulmonary emboli and was maintained on oral anticoagulation therapy. Recently, he presented with gradually progressive shortness of breath and signs of right ventricular failure. Diagnostic imaging: 1-Transthoracic and transesophageal echocardiography showed normal global systolic left ventricular function with no regional wall motion abnormalities, dilated right ventricle (RV) with moderately impaired function, severe pulmonic valve incompetence, mild tricuspid incompetence and a severely elevated right ventricular systolic pressure (RVSP) of 82 mmHg. In addition, a small rounded mass (6 x 11 mm) was visualized attached to the posterior wall of the RV outflow tract (RVOT) about 15mm proximal to the pulmonary valve annulus, (figure A). 2- Computed tomography pulmonary angiography showed a right main pulmonary artery (RPA) with circumferential narrowing, which was highly suggestive of chronic thrombosis. There was an abrupt tapering noted in the segmental branches of the right lower lobar pulmonary artery, with non-opacification of the distal arteries. No contrast opacification was noted in the right upper lobe pulmonary arteries. The left main pulmonary artery showed thickening of its bifurcation, again suggestive of chronic thrombosis, with narrowing of its left upper lobar branch, (figures B&C). 3-Cardiac magnetic resonance (CMR) showed a non enhancing RVOT mass protruding through the incompetent pulmonary valve during systole with features suggestive of a thrombus. Management In view of the clinical history, CTEPH was considered to be the most likely aetiology of the pulmonary hypertension. The decision was to perform balloon angioplasty and stent implantation in the RPA. Immediately after the procedure, RVSP was reduced from 80 to 50 mmHg. The clinical course after this procedure was uncomplicated and the patient showed significant clinical improvement. Follow up CMR showed patent stent with improvement of RV function ( fig D) Abstract P885 Figure.

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