6533b81ffe1ef96bd1278747
RESEARCH PRODUCT
Regulation of endothelial nitric oxide synthase (eNOS) in myocardium subjected to cardioplegic arrest.
Uwe M. FischerKlara BrixiusStock UOliver KlassCharles S. CoxWilhelm BlochA. AntonyanJh FischerUwe Mehlhornsubject
Pulmonary and Respiratory MedicineMaleThreoninemedicine.medical_specialtyTime FactorsNitric Oxide Synthase Type IIISwineHeart VentriclesIschemiaEnos phosphorylationVentricular Function LeftNitric oxidechemistry.chemical_compoundEnosInternal medicinemedicineSerineAnimalsPhosphorylationProtein kinase BMitogen-Activated Protein Kinase 1Cardiopulmonary BypassMitogen-Activated Protein Kinase 3Endothelial nitric oxide synthasebiologybusiness.industryMyocardiummedicine.diseasebiology.organism_classificationImmunohistochemistryMyocardial ContractionPathophysiologyEnzyme ActivationEndocrinologychemistryModels AnimalCardiologyHeart Arrest InducedPhosphorylationSurgeryFemaleCardiology and Cardiovascular MedicinebusinessProto-Oncogene Proteins c-aktdescription
BACKGROUND: Nitric oxide (NO) production by both coronary endothelial cells and cardiomyocytes is thought to play a significant role in myocardial pathophysiology following ischemia/reperfusion (I/R). METHODS: In thirteen pigs subjected to 1 hour cardioplegic arrest (CA) on CPB, left ventricular (LV) biopsies were collected prior to CPB (baseline), at 60 min CPA, at 15 and 30 min reperfusion on CPB, and at 120 min post CPB. LV specimens were immunocytochemically stained against phospho-eNOS Ser1177 , phospho-eNOS Thr495 , phosphorylated ERK1/2, and AKT/PKB. Four additional pigs without CA served as controls. Cardiomyocytes were quantitatively investigated using TV densitometry (gray units: U). RESULTS: After 60 min CA phosphorylation of eNOS Ser1177 increased significantly and remained elevated until 30 min of reperfusion. In contrast, eNOS Thr495 phosphorylation remained unchanged during CA and throughout reperfusion. In control animals, eNOS phosphorylation remained unchanged. Akt/PKB activity significantly increased after 60 min CA and decreased thereafter. ERK1/2 activity remained unchanged during ischemia but increased during reperfusion. CONCLUSIONS: ENOS activation during ischemia occurs through phosphorylation at Ser1177 mediated by Akt/PKB. ERK1/2 does not seem to be involved in myocardial eNOS regulation especially not via phosphorylation at eNOS Thr495 .
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2009-10-02 | The Thoracic and cardiovascular surgeon |