Background: Nitric oxide (NO), synthesised from the inducible isoform of nitric oxide synthase (iNOS), is implicated in mediating second window of protection (SWOP)/delayed ischemic preconditioning. However the role of NO and iNOS in delayed pharmacological protection remains unclear and is the subject of this investigation.
Methods: To test the hypothesis that iNOS is necessary for delayed pharmacological preconditioning, the adenosine A(1) receptor agonist, 2-chloro N(6) cyclopentyl adenosine (CCPA) (25 microg/kg i.v.) or saline was administered to wild type (WT) or iNOS gene knockout mice (KO). Twenty-four hours later, the hearts were isolated, Langendorff perfused and subjected to 35 min ischemia/30 min reperfusion prior to infarct size determination.
Results: WT and KO control hearts had identical infarct sizes of 37 +/- 3% and 37 +/- 2%, respectively. CCPA significantly reduced infarct size in WT hearts to 22 +/- 2% and also, unexpectedly, in KO hearts (27 +/- 2%). This protection was abrogated with the non-specific NOS inhibitor, N(omega) nitro L-arginine methyl ester (L-NAME, 100 microM), and could be mimicked in naïve hearts with the NO donor, donor S-nitroso N-acetyl DL penicillamine (SNAP, 1 microM). Delayed protection appeared to be mediated by NO synthesis in both WT and KO hearts. Additional studies using Western blot analysis demonstrated endothelial NOS (eNOS) upregulation and increased NO(x) release in both WT and KO hearts.
Conclusions: This is the first study to demonstrate a role for eNOS in delayed A(1) receptor triggered (pharmacological) preconditioning, potentially representing a new pharmacological target for protecting the ischemic heart.
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http://dx.doi.org/10.1016/s0008-6363(01)00472-2 | DOI Listing |
Invest Ophthalmol Vis Sci
January 2025
Cardiol Rev
January 2025
From the Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX.
The vascular endothelium and its endothelial glycocalyx contribute to the protection of the endothelial cells from exposure to high levels of sodium and help these structures maintain normal function by regulating vascular permeability due to its buffering effect. The endothelial glycocalyx has negative surface charges that bind sodium and limit sodium entry into cells and the interstitial space. High sodium levels can disrupt this barrier and allow the movement of sodium into cells and extravascular fluid.
View Article and Find Full Text PDFJ Liver Cancer
January 2025
Department of Gastroenterology, Liver Center, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
Background/aims: Hepatocellular carcinoma (HCC) is a malignant cancer with an increasing incidence worldwide. Although numerous efforts have been made to identify effective therapies for HCC, current strategies have limitations. We present a new approach for targeting L-arginine and argininosuccinate synthetase 1 (ASS1).
View Article and Find Full Text PDFZhonghua Yi Xue Za Zhi
January 2025
Department of Respiratory and Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou510515, China.
To investigate the characteristics of type 2 inflammation in patients with nocturnal asthma, and analyze the improvement of asthma symptoms after the use of inhaled corticosteroids (ICS) combined with different long-acting bronchodilators. Data of 231 asthma patients who first visited the Respiratory and Critical Care Medical Clinic of Nanfang Hospital of Southern Medical University from January 2020 to June 2023 and had positive bronchodilator tests (BDT), were retrospectively analyzed. These patients were divided into nocturnal asthma group and non-nocturnal asthma group based on the presence or absence of nocturnal symptoms.
View Article and Find Full Text PDFBMJ Open
December 2024
Research and Development Center for New Medical Frontiers, Department of Advanced Medicine, Division of Neonatal Intensive Care Medicine, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
Objectives: Inhaled nitric oxide (iNO) is a known treatment for pulmonary hypertension (PH) associated with bronchopulmonary dysplasia in preterm infants after 7 days of age (postacute phase). However, a consensus regarding the optimal criteria for initiating iNO therapy in this population in the postacute phase is currently lacking. This study, therefore, aimed to identify the criteria for initiating iNO therapy, alongside the associated clinical and echocardiographic findings, in this population.
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