scholarly journals Cardioprotective role of myocardial endothelial nitric oxide synthase and serum nitric oxide induced by hexarelin in rats with myocardial infarction-induced heart failure

Background: Growth hormone-releasing peptides (GHRP) have been reported to possess cardioprotective properties; nonetheless, their mechanisms of action are still not very clear. Objectives: Some studies have suggested that modulation of endothelial nitric oxide synthase (eNOS) and the upregulation of nitric oxide (NO) are cardioprotective. Therefore, the present study strived to test the hypothesis that a potent GHRP analog (hexarelin) could increase serum nitric oxide level and regulate myocardial eNOS to alleviate the development of heart failure. Methods: Myocardial infarction-induced heart failure in rats was established by permanent coronary artery ligation. The sham group, control group, and heart failure group all received normal saline (100 µg/kg; SC BID; 30days), while the rats in the hexarelin treatment group were treated with hexarelin (100 µg/kg, SC BID, 30 days). The rats were tested for myocardial apoptosis, oxidative stress, left ventricular function, various molecular analyses, as well as pathological and structural myocardial changes. Results: Hexarelin treatment improved contractile function and attenuated myocardial histopathological damages, oxidative stress, fibrosis, as well as apoptosis. All these were accompanied by the upregulation of myocardial eNOS and an increase in serum NO concentration. Conclusion: As evidenced by the obtained results, the anti-cardiac failure capacity of hexarelinin in a rat model is mediated by an increase in serum nitric oxide level and the up-modulation of myocardial eNOS; therefore, they can be considered therapeutic targets against heart failure.

Circulation ◽  
2001 ◽  
Vol 104 (11) ◽  
pp. 1286-1291 ◽  
Author(s):  
Marielle Scherrer-Crosbie ◽  
Roman Ullrich ◽  
Kenneth D. Bloch ◽  
Hiroshi Nakajima ◽  
Boris Nasseri ◽  
...  

Author(s):  
Chi-Ming Wei ◽  
Margarita Bracamonte ◽  
Shi-Wen Jiang ◽  
Richard C. Daly ◽  
Christopher G.A. McGregor ◽  
...  

Nitric oxide (NO) is a potent endothelium-derived relaxing factor which also may modulate cardiomyocyte inotropism and growth via increasing cGMP. While endothelial nitric oxide synthase (eNOS) isoforms have been detected in non-human mammalian tissues, expression and localization of eNOS in the normal and failing human myocardium are poorly defined. Therefore, the present study was designed to investigate eNOS in human cardiac tissues in the presence and absence of congestive heart failure (CHF).Normal and failing atrial tissue were obtained from six cardiac donors and six end-stage heart failure patients undergoing primary cardiac transplantation. ENOS protein expression and localization was investigated utilizing Western blot analysis and immunohistochemical staining with the polyclonal rabbit antibody to eNOS (Transduction Laboratories, Lexington, Kentucky).


2016 ◽  
Vol 310 (1) ◽  
pp. H39-H48 ◽  
Author(s):  
Masashi Mukohda ◽  
Madeliene Stump ◽  
Pimonrat Ketsawatsomkron ◽  
Chunyan Hu ◽  
Frederick W. Quelle ◽  
...  

Loss of peroxisome proliferator-activated receptor (PPAR)-γ function in the vascular endothelium enhances atherosclerosis and NF-κB target gene expression in high-fat diet-fed apolipoprotein E-deficient mice. The mechanisms by which endothelial PPAR-γ regulates inflammatory responses and protects against atherosclerosis remain unclear. To assess functional interactions between PPAR-γ and inflammation, we used a model of IL-1β-induced aortic dysfunction in transgenic mice with endothelium-specific overexpression of either wild-type (E-WT) or dominant negative PPAR-γ (E-V290M). IL-1β dose dependently decreased IκB-α, increased phospho-p65, and increased luciferase activity in the aorta of NF-κB-LUC transgenic mice. IL-1β also dose dependently reduced endothelial-dependent relaxation by ACh. The loss of ACh responsiveness was partially improved by pretreatment of the vessels with the PPAR-γ agonist rosiglitazone or in E-WT. Conversely, IL-1β-induced endothelial dysfunction was worsened in the aorta from E-V290M mice. Although IL-1β increased the expression of NF-κB target genes, NF-κB p65 inhibitor did not alleviate endothelial dysfunction induced by IL-1β. Tempol, a SOD mimetic, partially restored ACh responsiveness in the IL-1β-treated aorta. Notably, tempol only modestly improved protection in the E-WT aorta but had an increased protective effect in the E-V290M aorta compared with the aorta from nontransgenic mice, suggesting that PPAR-γ-mediated protection involves antioxidant effects. IL-1β increased ROS and decreased the phospho-endothelial nitric oxide synthase (Ser1177)-to-endothelial nitric oxide synthase ratio in the nontransgenic aorta. These effects were completely abolished in the aorta with endothelial overexpression of WT PPAR-γ but were worsened in the aorta with E-V290M even in the absence of IL-1β. We conclude that PPAR-γ protects against IL-1β-mediated endothelial dysfunction through a reduction of oxidative stress responses but not by blunting IL-1β-mediated NF-κB activity.


2014 ◽  
Vol 289 (40) ◽  
pp. 27540-27550 ◽  
Author(s):  
Sabine Kossmann ◽  
Hanhan Hu ◽  
Sebastian Steven ◽  
Tanja Schönfelder ◽  
Daniela Fraccarollo ◽  
...  

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