Phosphorylation of endothelial NOS contributes to simvastatin protection against myocardial no-reflow and infarction in reperfused swine hearts： partially via the PKA signaling pathway

• Published in: Acta pharmacologica Sinica Vol. 33; no. 7; pp. 879 - 887
• Main Authors: Li, Xiang-dong, Yang, Yue-jin, Geng, Yong-jian, Zhao, Jing-lin, Zhang, Hai-tao, Cheng, Yu-tong, Wu, Yi-ling
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01.07.2012; Nature Publishing Group
• Subjects: Animals; Anticholesteremic Agents - therapeutic use; Biomedical and Life Sciences; Biomedicine; Creatine Kinase - blood; Cyclic AMP Response Element-Binding Protein - metabolism; Cyclic AMP-Dependent Protein Kinases - metabolism; Heart - drug effects; Hemodynamics - drug effects; Immunology; Internal Medicine; Medical Microbiology; Myocardial Infarction - enzymology; Myocardial Infarction - pathology; Myocardial Infarction - prevention & control; Myocardial Reperfusion Injury - enzymology; Myocardial Reperfusion Injury - pathology; Myocardial Reperfusion Injury - prevention & control; Myocardium - enzymology; Myocardium - pathology; Nitric Oxide Synthase Type III - metabolism; Original; original-article; Pharmacology/Toxicology; Phosphorylation - drug effects; PKA; Signal Transduction - drug effects; Simvastatin - therapeutic use; Swine; Swine, Miniature; Vaccine; 保护; 信号通路; 内皮型一氧化氮合酶; 心肌梗死; 心肌缺血再灌注; 磷酸化; 辛伐他汀; ischemia-reperfusion injury; CREB; L-NNA; no-reflow; H-89; infarction; simvastatin; endothelial NOS; protein kinase A; heart
• ISSN: 1671-4083; 1745-7254
• DOI: 10.1038/aps.2012.27

Aim： The cholesterol-lowering drugs statins could enhance the activities of endothelial nitric oxide synthase （eNOS） and protect myocardium during ischemia and reperfusion. The aim of this study was to examine whether protein kinase A （PKA） was involved in statinmediated eNOS phosphorylation and cardioprotection. Methods： 6-Month-old Chinese minipigs （20-30 kg） underwent a 1.5-h occlusion and 3-h reperfusion of the left anterior descending coronary artery （LAD）. In the sham group, the LAD was encircled by a suture but not occluded. Hemodynamic and cardiac function was monitored using a polygraph. Plasma activity of creatine kinase and the tissue activities of PKA and NOS were measured spectrophotometrically, p-CREB, eNOS and p-eNOS levels were detected using Western blotting. Sizes of the area at risk, the area of no-reflow and the area of necrosis were measured morphologically. Results： Pretreatment of the animals with simvastatin （SIM, 2 mg/kg, po） before reperfusion significantly decreased the plasma activity of creatine kinase, an index of myocardial necrosis, and reduced the no-reflow size （from 50.4%±2.4% to 36.1%±2.1%, P〈0.01） and the infarct size （from 79.0%±2.7% to 64.1%±4.5%, P〈0.01）. SIM significantly increased the activities of PKA and constitutive NOS, and increased Sert33 p-CREB protein, Ser1179 p-eNOS, and Ser635 p-eNOS in ischemic myocardium. Intravenous infusion of the PKA inhibitor H-89 （1 mg.kg^-1.minl） partially abrogated the SlM-induced cardioprotection and eNOS phosphorylation. In contrast, intravenous infusion of the eNOS inhibitor L-NNA （10 mg.kg^-1） completely abrogated the SlM-induced cardioprotection and eNOS phosphorylation during ischemia and reperfusion, but did not affect the activity of PKA. Conclusion： Pretreatment with a single dose of SIM 2.5 h before reperfusion attenuates myocardial no-reflow and infarction through increasing eNOS phosphorylation at Ser^1179 and Ser635 that was partially mediated via the PKA signaling pathway.