Purpose: Although nitroxyl radicals such as 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) scavenge free radicals, their short half-life and considerable side effects such as systemic hypotension and bradycardia have limited their clinical application. Since a radical-containing nanoparticle (RNP) delivers nitroxyl radicals with a prolonged half-life specific to ischemic hearts, we investigated whether RNPs reduce infarct size without the occurrence of substantial side effects and whether nitric oxide (NO) contributes to the cardioprotective effects of RNPs.
Methods: The left anterior descending coronary arteries of dogs were occluded for 90 min, followed by reperfusion for 6 h. Either RNPs, micelles (not containing TEMPO) (control), or 4-hydroxy-TEMPO (TEMPOL) was injected into a systemic vein for 5 min before reperfusion. We evaluated the infarct size, myocardial apoptosis, plasma NO levels in coronary venous blood, and the RNP spectra using an electron paramagnetic resonance assay.
Results: RNPs reduced infarct size compared with the control group and TEMPOL group (19.5 ± 3.3 vs. 42.2 ± 3.7 vs. 30.2 ± 3.4%). RNPs also reduced myocardial apoptosis compared with the control and TEMPOL group. Coronary venous NO levels increased in the RNP group.
Conclusions: In conclusion, the administration of 2,2,6,6-tetramethylpiperidine-1-oxyl as a RNP exerted cardioprotective effects against ischemia and reperfusion injury in canine hearts without exerting unfavorable hemodynamic effects. RNPs may represent a promising new therapy for patients with acute myocardial infarction.
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http://dx.doi.org/10.1007/s10557-017-6758-6 | DOI Listing |
Front Pharmacol
December 2024
Department of Pharmacy, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China.
Introduction: In the last decades, the recombinant tissue plasminogen activator alteplase has been the standard fibrinolytic treatment of acute myocardial infarction, pulmonary embolism, and acute ischemic stroke. An optimized version of alteplase, tenecteplase, has been developed by exchanging six amino acids to increase half-life, achieve higher fibrin selectivity and increase resistance to plasminogen activator inhibitor-1. Meanwhile, several products containing tenecteplase exist.
View Article and Find Full Text PDFCardiovasc Res
January 2025
Research Institute, Hospital de la Santa Creu i Sant Pau, IIB-Sant Pau, Barcelona, Spain.
Aims: Recurrent acute myocardial infarction (RE-AMI) is a frequent complication after STEMI, and its association with stent thrombosis can be life-threatening. Intravenous atorvastatin (IV-atorva) administration during AMI has been shown to limit infarct size and adverse cardiac remodeling. We determined by cardiac magnetic resonance (CMR) whether the cardioprotection exerted by IV-atorva at the index AMI event translates into a better prognosis upon RE-AMI in dyslipidemic pigs.
View Article and Find Full Text PDFChem Biol Drug Des
January 2025
Department of Anesthesiology, The First Affiliated Hospital, Jiangxi Medical College, Nanchang University, Nanchang, Jiangxi Province, China.
Cerebral ischemia/reperfusion injury (IRI) is pathologically associated with ferroptosis. Dexmedetomidine (Dex) exerts neuroprotective activity after cerebral IRI. Our work focused on probing the pharmacologic effect of Dex on ferroptosis during cerebral IRI and the mechanisms involved.
View Article and Find Full Text PDFCardiovasc Drugs Ther
January 2025
The Hatter Cardiovascular Institute, University College London, 67 Chenies Mews, London, WC1E 6HX, UK.
Purpose: Reperfusion of the ischaemic heart is essential to limit myocardial infarction. However, reperfusion can cause cardiomyocyte hypercontracture. Recently, cardiac myosin-targeted inhibitors (CMIs), such as Mavacamten (MYK-461) and Aficamten (CK-274), have been developed to treat patients with cardiac hypercontractility.
View Article and Find Full Text PDFInt J Stroke
January 2025
Department of Neurosurgery and Interventional Neuroradiology, Xuanwu Hospital, China International Neuroscience Institute, Capital Medical University, National Center for Neurological Disorders, 45 Changchun St, Beijing 100053, China.
Rationale: The Chemical Optimization of Cerebral Embolectomy (CHOICE) trial suggested that the administration of intra-arterial alteplase after successful endovascular thrombectomy (EVT) may improve neurological outcomes in patients with acute ischemic stroke due to large vessel occlusion (AIS-LVO) in the anterior circulation. However, the use of adjunctive intra-arterial alteplase following successful EVT in acute posterior circulation stroke remains unexplored.
Aims: This study aims to investigate the efficacy and safety of intra-arterial alteplase after successful EVT for AIS-LVO in the posterior circulation.
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