Alpha-skeletal actin messenger RNA increases in acute right ventricular hypertrophy

1990 ◽  
Vol 258 (4) ◽  
pp. L173-L178 ◽  
Author(s):  
P. R. Bakerman ◽  
K. R. Stenmark ◽  
J. H. Fisher
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Hypobaric Hypoxia ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Hypoxic Exposure ◽  
Mrna Levels ◽  
Severe Pulmonary Hypertension ◽  
Cardiac Actin ◽  
Actin Mrna

Newborn calves exposed to hypobaric hypoxia develop severe pulmonary hypertension. Right ventricular hypertrophy and failure occur as a consequence of the increased pressure load. Alterations in right ventricular myocyte performance or differentiation could be reflected by the changes in the expression of contractile protein genes. We studied expression of contractile actin isotypes by measuring mRNA levels in total cellular RNA purified from right (RV) and left ventricles (LV) of calves with severe pulmonary hypertension after a 2-wk exposure to hypobaric hypoxia and age-matched controls. alpha-Skeletal actin mRNA was increased greater than 10-fold in the RV of hypertensive animals, whereas alpha-cardiac actin mRNA did not appear to change. alpha-Skeletal actin mRNA and alpha-cardiac actin mRNA did not increase in the LV of any of the hypoxic animals. After a 2-wk hypoxic exposure, calves were removed from the chamber. Two days later, RV alpha-skeletal actin mRNA decreased dramatically but was apparently elevated above that of an age-matched control. Thirty days after hypoxia, there appeared to be a persistent increase in RV alpha-skeletal actin mRNA. Although the physiological significance of these changes are unknown, an alteration in the RV myocyte phenotype has occurred.

scholarly journals Generation of oxidative stress contributes to the development of pulmonary hypertension induced by hypoxia

2001 ◽  
Vol 90 (4) ◽  
pp. 1299-1306 ◽  
Author(s):  
Yasushi Hoshikawa ◽  
Sadafumi Ono ◽  
Satoshi Suzuki ◽  
Tatsuo Tanita ◽  
Masayuki Chida ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Hypoxic Exposure ◽  
Induction Phase ◽  
Pulmonary Vascular Remodeling ◽  
Effect Of Treatment

Chronic hypoxia causes pulmonary hypertension and right ventricular hypertrophy associated with pulmonary vascular remodeling. Because hypoxia might promote generation of oxidative stress in vivo, we hypothesized that oxidative stress may play a role in the hypoxia-induced cardiopulmonary changes and examined the effect of treatment with the antioxidant N-acetylcysteine (NAC) in rats. NAC reduced hypoxia-induced cardiopulmonary alterations at 3 wk of hypoxia. Lung phosphatidylcholine hydroperoxide (PCOOH) increased at days 1 and 7 of the hypoxic exposure, and NAC attenuated the increase in lung PCOOH. Lung xanthine oxidase (XO) activity was elevated from day 1 through day 21, especially during the initial 3 days of the hypoxic exposure. The XO inhibitor allopurinol significantly inhibited the hypoxia-induced increase in lung PCOOH and pulmonary hypertension, and allopurinol treatment only for the initial 3 days also reduced the hypoxia-induced right ventricular hypertrophy and pulmonary vascular thickening. These results suggest that oxidative stress produced by activated XO in the induction phase of hypoxic exposure contributes to the development of chronic hypoxic pulmonary hypertension.

Simvastatin causes endothelial cell apoptosis and attenuates severe pulmonary hypertension

2006 ◽  
Vol 291 (4) ◽  
pp. L668-L676 ◽  
Author(s):  
Laimute Taraseviciene-Stewart ◽  
Robertas Scerbavicius ◽  
Kang-Hyeon Choe ◽  
Carlyne Cool ◽  
Kathy Wood ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Endothelial Cell ◽  
Right Ventricular ◽  
Cell Apoptosis ◽  
Ventricular Hypertrophy ◽  
Caspase 3 ◽  
Right Ventricular Hypertrophy ◽  
Severe Pulmonary Hypertension ◽  
Endothelial Cell Apoptosis ◽  
Microvascular Endothelial

Severe pulmonary hypertension (SPH) is characterized by precapillary arteriolar lumen obliteration, dramatic right ventricular hypertrophy, and pericardial effusion. Our recently published rat model of SPH recapitulates major components of the human disease. We used this model to develop new treatment strategies for SPH. SPH in rats was induced using VEGF receptor blockade in combination with chronic hypoxia. A large variety of drugs used in this study, including anticancer drugs (cyclophosphamide and paclitaxel), the angiotensin-converting enzyme inhibitor lisinopril, the antiangiogenic agent thalidomide, and the peroxisome proliferator-actived receptor-γ agonist PGJ2, failed to decrease mean pulmonary artery pressure (PAP) or right ventricular hypertrophy. In contrast, treatment of rats with established SPH with simvastatin markedly reduced mean PAP and right ventricular hypertrophy, and this reduction was associated with caspase-3 activation and pulmonary microvascular endothelial cell apoptosis. Simvastatin partially restored caveolin-1, caveolin-2, and phospho-caveolin expression in vessel walls. In rat primary pulmonary microvascular endothelial cells, simvastatin induced caspase 3 activation and Rac 1 expression while suppressing Rho A and attenuated levels of Akt and ERK phosphorylation. We conclude that simvastatin is effective in inducing apoptosis in hyperproliferative pulmonary vascular lesions and could be considered as a potential drug for treatment of human SPH.

scholarly journals Differential Expression of Three Hypoxia-inducible Factor-α Subunits in Pulmonary Arteries of Rat with Hypoxia-induced Hypertension

2005 ◽  
Vol 37 (10) ◽  
pp. 665-672 ◽  
Author(s):  
Qi-Fang Li ◽  
Ai-Guo Dai
Keyword(s):  
Pulmonary Hypertension ◽  
Western Blot ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Target Genes ◽  
Expression Patterns ◽  
Pulmonary Arteries ◽  
Right Ventricular Hypertrophy ◽  
Mrna Levels ◽  
Α Subunits

AbstractHypoxia inducible transcription factor (HIF)-1α plays an important role in the development of hypoxic pulmonary hypertension, but little is known about HIF-2α and HIF-3α with respect to transcriptional regulation by hypoxia. To examine the expression patterns of all HIF-α subunits (HIF-1α, HIF-2α and HIF-3α) in pulmonary arteries of rats undergoing systemic hypoxia, five groups of healthy male Wistar rats were exposed to normoxia (N) and hypoxia for 3 (H3), 7 (H7), 14 (H14) and 21 (H21) d respectively. Mean pulmonary arterial pressure (mPAP), vessel morphometry and right ventricular hypertrophy index were measured. Lungs were inflation fixed for immunohistochemistry and in situ hybridization, and homogenized for Western blot. mPAP increased significantly after 7 d of hypoxia [(18.4±0.4) vs. (14.4±0.4) mmHg, H7 vs. N], reached its peak after 14 d of hypoxia, then remained stable. Pulmonary artery remodeling and right ventricular hypertrophy developed significantly after 14 d of hypoxia. During normoxia, HIF-1α and HIF-3α staining were slightly positive regarding mRNA levels. A substantial alteration of HIF-1α and HIF-3α staining occurred in pulmonary arteries after 14 d and 7 d of hypoxia, respectively, but HIF-2α staining showed an inversed trend after 14 d of hypoxia. Protein levels of all HIF-α subunits except HIF-3α showed a marked increase corresponding to the duration of hypoxia, which was obtained by Western blot. Our study found that HIF-1α, HIF-2α and HIF-3α may not only confer different target genes, but also play key pathogenetic roles in hypoxic-induced pulmonary hypertension.

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.

scholarly journals Bosentan attenuates right ventricular hypertrophy and fibrosis in normobaric hypoxia model of pulmonary hypertension

2011 ◽  
Vol 30 (7) ◽  
pp. 827-833 ◽  
Author(s):  
Gaurav Choudhary ◽  
Frederick Troncales ◽  
Douglas Martin ◽  
Elizabeth O. Harrington ◽  
James R. Klinger
Keyword(s):  
Pulmonary Hypertension ◽  
Right Ventricular ◽  
Ventricular Hypertrophy ◽  
Right Ventricular Hypertrophy ◽  
Normobaric Hypoxia
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