Activation of the right ventricular endothelin (ET) system in the monocrotaline model of pulmonary hypertension: response to chronic ETA receptor blockade

2003 ◽  
Vol 105 (6) ◽  
pp. 647-653 ◽  
Author(s):  
Jean-François JASMIN ◽  
Peter CERNACEK ◽  
Jocelyn DUPUIS
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Lower Percentage ◽  
Receptor Blockade ◽  
Eta Receptor ◽  
Eta Receptor Antagonist ◽  
The Right

Although activation of the endothelin (ET) system contributes to pulmonary hypertension, modifications of the cardiopulmonary ET system and its responses to chronic ET receptor blockade are not well known. To investigate this, rats were injected with monocrotaline (60 mg/kg intraperitoneal) or saline, followed with treatment with the selective ETA receptor antagonist LU135252 (LU; 50 mg·kg-1·day-1) or with saline. After 3 weeks, haemodynamics, cardiac hypertrophy, ET-1 levels and cardiopulmonary ET-receptor-binding profile were evaluated. Monocrotaline (n=7) elicited marked pulmonary hypertension and right ventricular hypertrophy compared with controls (n=8). Both variables were substantially attenuated by LU therapy (n=8; P<0.05 for both). After monocrotaline, right ventricular ET-1 levels were more significantly increased than in the left ventricle (+198% compared with +127%; P<0.05). ETB receptor density was augmented (3-fold) in the right ventricle, whereas that of ETA receptors was not affected. LU treatment also significantly attenuated these alterations (P<0.05). In the lungs, ET-1 levels were not increased after monocrotaline, whereas the balance of ETB to ETA receptors was altered, with a trend toward a lower percentage of ETB than in the control rats. LU treatment did not affect these variables in the lungs. Therefore monocrotaline-induced pulmonary hypertension and right ventricular hypertrophy are associated with the up-regulation of ET-1 and ETB receptors in the right ventricle. These alterations are attenuated with the reduction of pulmonary hypertension and right ventricular hypertrophy after chronic blockade of the ETA receptors, supporting the role of the ET system in right ventricular hypertrophy.

Cystamine Treatment Fails to Prevent the Development of Pulmonary Hypertension in Chronic Hypoxic Rats

2021 ◽  
pp. 1-15
Author(s):  
Lars K. Markvardsen ◽  
Lene D. Sønderskov ◽  
Christine Wandall-Frostholm ◽  
Estéfano Pinilla ◽  
Judit Prat-Duran ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Lung Tissue ◽  
Ventricular Hypertrophy ◽  
Systolic Pressure ◽  
Right Ventricular Hypertrophy ◽  
Ventricular Systolic Pressure ◽  
Pulmonary Arterial ◽  
The Right

<b><i>Introduction:</i></b> Pulmonary hypertension is characterized by vasoconstriction and remodeling of pulmonary arteries, leading to right ventricular hypertrophy and failure. We have previously found upregulation of transglutaminase 2 (TG2) in the right ventricle of chronic hypoxic rats. The hypothesis of the present study was that treatment with the transglutaminase inhibitor, cystamine, would inhibit the development of pulmonary arterial remodeling, pulmonary hypertension, and right ventricular hypertrophy. <b><i>Methods:</i></b> Effect of cystamine on transamidase activity was investigated in tissue homogenates. Wistar rats were exposed to chronic hypoxia and treated with vehicle, cystamine (40 mg/kg/day in mini-osmotic pumps), sildenafil (25 mg/kg/day), or the combination for 2 weeks. <b><i>Results:</i></b> Cystamine concentration-dependently inhibited TG2 transamidase activity in liver and lung homogenates. In contrast to cystamine, sildenafil reduced right ventricular systolic pressure and hypertrophy and decreased pulmonary vascular resistance and muscularization in chronic hypoxic rats. Fibrosis in the lung tissue decreased in chronic hypoxic rats treated with cystamine. TG2 expression was similar in the right ventricle and lung tissue of drug and vehicle-treated hypoxic rats. <b><i>Discussion/Conclusions:</i></b> Cystamine inhibited TG2 transamidase activity, but cystamine failed to prevent pulmonary hypertension, right ventricular hypertrophy, and pulmonary arterial muscularization in the chronic hypoxic rat.

ETA-receptor antagonist prevents and reverses chronic hypoxia-induced pulmonary hypertension in rat

1995 ◽  
Vol 269 (5) ◽  
pp. L690-L697 ◽  
Author(s):  
V. S. DiCarlo ◽  
S. J. Chen ◽  
Q. C. Meng ◽  
J. Durand ◽  
M. Yano ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Receptor Antagonist ◽  
Vascular Remodeling ◽  
Ventricular Hypertrophy ◽  
Chronic Hypoxia ◽  
Right Ventricular Hypertrophy ◽  
Pulmonary Vascular Remodeling ◽  
Eta Receptor ◽  
Eta Receptor Antagonist

The selective endothelin-A (ETA)-receptor antagonist BQ-123 has been shown to prevent chronic hypoxia-induced pulmonary hypertension in the rat. Therefore in the current study we utilized BQ-123 to test the hypothesis that blockade of the ETA receptor can reverse as well as prevent the increase in mean pulmonary artery pressure, right ventricle-to-left ventricle plus septum ratio, and percent wall thickness in small (50-100 microns) pulmonary arteries observed in male Sprague-Dawley rats exposed to normobaric hypoxia (10% O2, 2 wk). Infusion of BQ-123 (0.4 mg.0.5 microliter-1.h-1 for 2 wk in 10% O2) begun after 2 wk of hypoxia significantly reversed the established pulmonary hypertension and prevented further progression of right ventricular hypertrophy during the third and fourth week of hypoxia. BQ-123 infusion instituted before exposure to hypoxia completely prevented the hypoxia-induced pulmonary hypertension, right ventricular hypertrophy, and pulmonary vascular remodeling. These findings suggest that, in the lung, hypoxia induced an increase synthesis of endothelin-1, which acts locally on ETA receptors to cause pulmonary hypertension, right heart hypertrophy, and pulmonary vascular remodeling, while ETA-receptor blockade can both prevent and reverse these processes.

Transient severe isolated right ventricular hypertrophy in neonates

2003 ◽  
Vol 13 (4) ◽  
pp. 384-386 ◽  
Author(s):  
Munesh Tomar ◽  
Sitaraman Radhakrishnan ◽  
Savitri Shrivastava
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Ventricular Function ◽  
Ventricular Hypertrophy ◽  
Pressure Overload ◽  
Posterior Wall ◽  
Right Ventricular Hypertrophy ◽  
Pulmonary Vasculature ◽  
Normal Thickness ◽  
The Right

We report two instances of transient isolated right-sided myocardial hypertrophy in patients with an intact ventricular septum, normal thickness of the posterior wall of the left ventricle, and normal ventricular function, diagnosed by echocardiography on the third day of life. The two neonates, born at 36 and 38 weeks gestation respectively, had perinatal distress. Both were diagnosed as having isolated right ventricular hypertrophy with mild pulmonary hypertension, which disappeared in both cases within 8 weeks without any specific therapy. Though the cause of the ventricular hypertrophy remains unclear, we believe that it is the consequence of remodeling of pulmonary vasculature secondary to acute perinatal distress, resulting in persistent pulmonary hypertension and producing pressure overload on the right ventricle, and hence right ventricular hypertrophy. The finding of early and transient right ventricular hypertrophy, with normal left-sided structures and normal ventricular function, has thus far failed to gain attention in the paediatric cardiologic literature.

Dynamic changes of gene expression in hypoxia-induced right ventricular hypertrophy

2004 ◽  
Vol 286 (3) ◽  
pp. H1185-H1192 ◽  
Author(s):  
Saumya Sharma ◽  
Heinrich Taegtmeyer ◽  
Julia Adrogue ◽  
Peter Razeghi ◽  
Shiraj Sen ◽  
...  
Keyword(s):  
Right Ventricle ◽  
Right Ventricular ◽  
Pyruvate Dehydrogenase ◽  
Hypobaric Hypoxia ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Pyruvate Dehydrogenase Kinase ◽  
Myosin Isoforms ◽  
Pyruvate Dehydrogenase Kinase 4 ◽  
The Right

Hypobaric hypoxia induces right ventricular hypertrophy. The relative contribution of pulmonary hypertension, decreased arterial oxygen, and neuroendocrine stimulation to the transcriptional profile of hypoxia-induced right ventricular hypertrophy is unknown. Whereas both ventricles are exposed to hypoxia and neuroendocrine stimulation, only the right ventricle is exposed to increased load. We postulated that right ventricular hypertrophy would reactivate the fetal gene transcriptional profile in response to increased load. We measured the expression of candidate genes in the right ventricle of rats exposed to hypobaric hypoxia (11% O2) and compared the results with the left ventricle. Hypoxia induced right ventricular hypertrophy without fibrosis. In the right ventricle only, atrial natriuretic factor transcript levels progressively increased starting at day 7. Metabolic genes were differentially regulated, suggesting a substrate switch from fatty acids to glucose during early hypoxia and a switch back to fatty acids by day 14. There was also a switch in myosin isogene expression and a downregulation of sarcoplasmic/endoplasmic ATPase 2a during early hypoxia, whereas later, both myosin isoforms and SERCA2a were upregulated. When the right and left ventricle were compared, the transcript levels of all genes, except for myosin isoforms and pyruvate dehydrogenase kinase-4, differed dramatically suggesting that all these genes are regulated by load. Our findings demonstrate that hypoxia-induced right ventricular hypertrophy transiently reactivates the fetal gene program. Furthermore, myosin iso-gene and pyruvate dehydrogenase kinase-4 expression is not affected by load, suggesting that either hypoxia itself or neuroendocrine stimulation is the primary regulator of these genes.

Lung vessel leak precedes right ventricular hypertrophy in monocrotaline-treated rats

1983 ◽  
Vol 54 (2) ◽  
pp. 371-374 ◽  
Author(s):  
T. Sugita ◽  
T. M. Hyers ◽  
I. M. Dauber ◽  
W. W. Wagner ◽  
I. F. McMurtry ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Dry Weight ◽  
Lavage Fluid ◽  
Right Ventricular Hypertrophy ◽  
Lung Water ◽  
Cell Hyperplasia ◽  
Albumin Content ◽  
The Right

Monocrotaline induces microvascular leak and pulmonary hypertension in rats. We have hypothesized that the leak is related in some way to the pulmonary hypertension and precedes it. In rats given 40 mg monocrotaline/kg body wt subcutaneously, lung wet weight-to-dry weight ratios and lung albumin content began to increase within the first 3 days and became maximal at 1 wk. Alveolar lavage fluid showed little or no increase in protein. Right ventricular hypertrophy increased progressively from 2 through 3 wk. An increase in lung dry weight paralleled the right ventricular hypertrophy. The amount of blood retained in the lung did not account for the increased lung water, albumin, or weight. We considered that microvascular leak without leak into the alveolar space preceded pulmonary hypertension, right ventricular hypertrophy, and increased lung dry weight. In rats not given monocrotaline but exposed for 3 wk to hypobaric hypoxia, lung albumin, lung dry weight, and right ventricular weight increased. Increased lung dry weight probably reflects hyperplasia of lung cells. If so, an association of microvascular leak, lung cell hyperplasia, and right ventricular hypertrophy may occur in both monocrotaline- and hypoxia-induced pulmonary hypertension.

Neither anticoagulant nor nonanticoagulant heparin affects monocrotaline lung injury

1987 ◽  
Vol 62 (2) ◽  
pp. 816-820 ◽  
Author(s):  
J. W. Fasules ◽  
K. R. Stenmark ◽  
P. M. Henson ◽  
N. F. Voelkel ◽  
J. T. Reeves
Keyword(s):  
Pulmonary Hypertension ◽  
Lung Injury ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Vascular Leak ◽  
Hypoxic Pulmonary Hypertension ◽  
Antiproliferative Agent ◽  
The Right ◽  
Insight Into

The administration of monocrotaline to rats causes pulmonary vascular leak within 1 wk followed in 2–3 wk by perivascular proliferation and fatal pulmonary hypertension. Possibly blocking the proliferation might block the pulmonary hypertension, providing insight into its mechanism. Because heparin, given as an antiproliferative agent, reduced hypoxic pulmonary hypertension in mice, it might also block monocrotaline-induced pulmonary hypertension. Alternatively, anticoagulation could worsen the lung injury. We found that heparin (300 and 600 U/kg sc twice daily) inhibited clotting in rats given monocrotaline but did not change the vascular leak, the right ventricular pressure, the right ventricular hypertrophy, the increased medial thickness of the pulmonary arterioles, or the production of a slow-reacting substance of anaphylaxis-like material by the lungs. A nonanticoagulant heparin fragment (2 mg/kg sc twice daily), given to avoid anticoagulation also did not influence the monocrotaline injury. Thus neither anticoagulant nor nonanticoagulant heparin either attenuated or worsened the measured effects of monocrotaline.

scholarly journals P270 Complex cyanotic heart disease in adult patient with down syndrome accompanied by mild pulmonary hypertension

2020 ◽  
Vol 21 (Supplement_1) ◽  
Author(s):  
A Siama ◽  
P Fountoulakis ◽  
A Tsoukas ◽  
A J Manolis
Keyword(s):  
Down Syndrome ◽  
Heart Disease ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Cyanotic Heart Disease ◽  
History Of ◽  
The Right ◽  
Bidirectional Flow

Abstract Funding Acknowledgements No funding Introduction Patients with Down syndrome and complex unrepaired cyanotic heart disease have impaired life expectancy. The clinical status of each patient depends both on the primary lesion type as well as the cummulative haemodynamic burden in the cardiovascular system. Assessment of an adult patient with complex congenital heart disease that has not been surgically repaired presents several challenges since initial haemodynamic parameters and compensatory mechanisms have to be taken into account. Case presentation A 43 year old male patient with known history of Down syndrome and no regular follow up presented to the Outpatient Department of our hospital to undergo pre-operative control for minor soft tissue surgery. The patient exhibited typical morphological features of Down syndrome as well as central cyanosis and digital clubbing. On auscultation a holosystolic type murmur 3/6 on the 3rd left parasternal border was audible. His blood gases revealed hypoxia and mild metabolic acidosis. Electrocardiogram displayed right axis deviation and signs of right ventricular hypertrophy. Transthoracic echocardiography demonstrated a large perimembranous ventricular septal defect (VSD) with normal anatomy and function of the aortic valve and no overiding aorta. Of note was excessive infundibular subpulmonary stenosis which resulted in a functionally double chambered right ventricle. Left ventricle was of normal diamater with good overall systolic function while the right ventricle was non-dilated with significant hypertrophy. Intracavitary gradient was estimated at 60 mmHg. Continuous Doppler showed mild mitral regurgitaion and mild tricuspid regurgitaion with estimated systolic pulmonary pressure of 40 mmHg. Bidirectional flow with low velocities at the level of the defect was recorded. Inferior vena cava was mildly dilated with normal respiratory variation. Discussion/ Conclusion: The natural history of large VSDs results in progressive dilatation of the right ventricle, the left ventricle and the left atrium with gradually increasing pylmonary vascular resistance and development of pulmonary hypertension, followed by right ventricular hypertrophy, flow reversal and Eisenmenger syndrome. However when RVOT obstruction at any level coexists, significant right ventricular hypertrophy develops and the incresed right ventricular systolic pressures acts protectively by minimizing the shunt at the VSD level. Thus a restrictive VSD due to a functionally double chambered right ventricle created a very fragile balance; a cyanotic heart disease with mild bidirectional flow depending on preload and afterload conditions that survived to adulthood. Abstract P270 Figure. Complex unrepaired CHD

Right ventricular hypertrophy in animals at high altitude

1963 ◽  
Vol 18 (5) ◽  
pp. 913-918 ◽  
Author(s):  
Herbert N. Hultgren ◽  
Emilio Marticorena ◽  
Harry Miller
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Sea Level ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Moderate Degree ◽  
Peruvian Andes ◽  
Mean Pressure ◽  
Septal Hypertrophy ◽  
The Right

The weight of the ventricles and septum in formalin-fixed hearts were determined in six animal species living continuously at altitudes between 10,000 and 15,400 ft in the central Peruvian Andes. Control studies were made of a similar number of hearts obtained from sea-level animals. Guinea pigs, rabbits, dogs, lambs, pigs, and steers all exhibited a moderate hypertrophy of the right ventricle roughly equivalent to a 25% increase in weight. A lesser degree of septal hypertrophy occurred in all animals except steers. The data suggest that a moderate degree of pulmonary hypertension is the probable cause of the right ventricular hypertrophy. In steers this would be roughly the equivalent of a mean pressure of 35 mm Hg at 11,800 ft compared with sea-level pressures of 24 mm Hg. ventricular hypertrophy; altitude; pulmonary hypertension; lambs; pigs; steers Submitted on December 3, 1962

Sign in / Sign up

Export Citation Format

Share Document