Fifteen long-lived and fifteen young healthy subjects were enrolled in this study to verify the involvement of age-associated oxidative challenge in the mechanisms that control platelet activation. Our results showed in old subjects an enhancement of ex vivo platelet responsiveness to ADP and collagen, measured both in whole blood and in platelet rich plasma, an increased cytosolic calcium content, a decreased membrane fluidity and a lower intraplatelet nitrate/nitrite (NO(x)) amount. Additionally, an increased plasma content of peroxidative by-products (TBARS) and a decreased antioxidant plasma capacity together with a reduced lag time for in vitro oxidation of low density lipoprotein (LDL) and a diminished plasma NO(x) bioavailability were observed in aged subjects. Lag time for LDL oxidation was negatively correlated with plasma TBARS level, and positively correlated with intraplatelet NO(x) content. Findings of this study may support the speculation that advancing age increases the susceptibility of LDL to oxidative modifications and favors platelet activation by oxidized LDL-induced decrease of nitric oxide bioactivity.
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Thromb Haemost
January 2025
Department of Medical Physiology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
Background: Fibrinolysis is spatiotemporally well-regulated and greatly influenced by activated platelets and coagulation activity. Our previous real-time imaging analyses revealed that clotting commences on activated platelet surfaces, resulting in uneven-density fibrin structures, and that fibrinolysis initiates in dense fibrin regions and extends to the periphery. Despite the widespread clinical use of direct oral anticoagulants (DOACs), their impact on thrombin-dependent activation of thrombin-activatable fibrinolysis inhibitor (TAFI) and fibrinolysis remains unclear.
View Article and Find Full Text PDFComorbid diabetes mellitus (DM) in patients with ischemic heart disease (IHD) is a serious factor that significantly impairs the life prognosis and increases the risk of cardiovascular complications (CVC) as well as the likelihood of death. The residual risk of developing CVC in such patients is largely determined by the high thrombotic status, that is associated with hypercoagulation characteristic of DM. Hypercoagulation causes activation of both platelet and coagulation pathways, which leads to an increased susceptibility to thrombosis.
View Article and Find Full Text PDFCardiovasc Res
January 2025
State Key Laboratory of Cardiovascular Disease, Clinical Pharmacology Center, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100037, China.
Aims: The therapeutic efficacy of coronary revascularization is compromised by myocardial ischemia-reperfusion (MI/R) injury. Higher levels of circulating arachidonic acid (AA) are reportedly associated with lower risk of cardiovascular disease. The cyclooxygenase (COX) pathway metabolizes AA into prostaglandins (PGs) and the platelet-activating thromboxane A2 (TXA2), which is inhibited by aspirin.
View Article and Find Full Text PDFJ Am Coll Cardiol
January 2025
Division of Biostatistics and Health Services Research, Department of Population and Quantitative Health Sciences, University of Massachusetts Chan Medical School, Worcester, Massachusetts, USA.
Background: Systemic thromboxane A generation, which is readily assessed by quantifying thromboxane B metabolites (TXB-M) in the urine, is associated with impaired cardiac performance and mortality in aspirin (ASA) users with heart failure (HF).
Objectives: This study sought to determine the association of urinary TXB-M with the risk of developing HF in individuals without prior history of HF and with normal left ventricular function irrespective of ASA use.
Methods: Urine TXB-M were measured by immunoassay and adjusted to urine concentration and renal function (TXB-M) in 2,611 Framingham Heart Study participants (54.
Vox Sang
January 2025
Department of Laboratory Sciences, School of Paramedical and Rehabilitation Sciences, Mashhad University of Medical Sciences, Mashhad, Iran.
Background And Objectives: Although transfusion reactions occur in less than 2% of recipients, they are currently one of the most serious concerns in blood transfusion. Damage-associated molecular patterns (DAMPs) are released from injured, stressed or dead cells, leading to inflammation and immune system activation. One of the recognized DAMPs is mitochondrial DNA (mtDNA).
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