Background And Objectives: Complete and persistent suppression of platelet thromboxane (TX) A(2) biosynthesis by aspirin is mandatory to fulfill its cardioprotection. We explored the determinants of heterogeneity of TXB2 generation in clotting whole blood, a capacity index of platelet cyclooxygenase (COX) activity, in patients with coronary heart disease (CHD) versus healthy subjects treated with low-dose aspirin on a long-term basis.
Methods: We studied 30 patients with CHD (ie, chronic stable angina, unstable angina, and acute myocardial infarction) and 10 healthy subjects, who were treated with low-dose aspirin (100 mg daily) on a long-term basis, 12 hours after the administration of 160 mg aspirin to ensure saturation of platelet COX-1 activity. Serum TXB2 levels were assessed. The contribution of blood COX-2 to TXA2 biosynthesis was explored by evaluation of the effect of a selective COX-2 inhibitor (L-745,337) added to heparinized whole blood stimulated with Ca++ ionophore A23187 (20 micromol/L) for 1 hour or lipopolysaccharide (0.1 microg/mL) for 4 hours.
Results: In healthy subjects serum TXB2 levels ranged from 0.6 to 7.9 ng/mL (median, 2.1 ng/mL; mean +/- SD, 3.2 +/- 2.6 ng/mL). In CHD patients we detected enhanced variability in serum TXB2 generation (median, 3.1 ng/mL [range, 0.15-47 ng/mL]; mean, 8.5 +/- 12.3 ng/mL), which in 8 patients (27%) exceeded the mean value + 2 SDs detected in healthy subjects (ie, 8.4 ng/mL), set as the limit value for an adequate inhibition of platelet COX-1 by aspirin. Elevated whole-blood TXB2 generation was not dependent on leukocyte count, COX-2 activity, or cigarette smoking but was plausibly a result of defective suppression of platelet COX-1 activity.
Conclusions: Heterogeneity in the suppression of platelet COX-1 activity by aspirin occurred in CHD patients. The measurement of the serum TXB2 level seems to be an appropriate biomarker to identify patients who have an inadequate inhibition of platelet COX-1 activity by aspirin.
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http://dx.doi.org/10.1016/j.clpt.2006.04.011 | DOI Listing |
Front Pharmacol
December 2024
Systems Pharmacology and Translational Therapeutics Laboratory, The Center for Advanced Studies and Technology (CAST), "G. d'Annunzio" University, Chieti, Italy.
Inflammation plays a critical role in the pathogenesis of various diseases by promoting the acquisition of new functional traits by different cell types. Shared risk factors between cardiovascular disease and cancer, including smoking, obesity, diabetes, high-fat diet, low physical activity, and alcohol consumption, contribute to inflammation linked to platelet activation. Platelets contribute to an inflammatory state by activating various normal cells, such as fibroblasts, immune cells, and vascular cells.
View Article and Find Full Text PDFFront Pharmacol
November 2024
Systems Pharmacology and Translational Therapeutics Laboratory, at the Center for Advanced Studies and Technology (CAST), and Department of Neuroscience, Imaging and Clinical Science, "G. d'Annunzio" University, Chieti, Italy.
Background: PPARα and cyclooxygenase (COX)-2 are overexpressed in certain types of cancer. Thus, developing a dual inhibitor that targets both could be more effective as an anticancer agent than single inhibitors. We have previously shown that an analog of the bezafibrate named AA520 is a PPARα antagonist.
View Article and Find Full Text PDFNihon Eiseigaku Zasshi
December 2024
Department of Preventive Medicine, Hyogo Medical University Faculty of Medicine.
The relationship between alcohol consumption and incident ischemic heart disease and stroke is characterized by a J- or U-shape. This denotes that light drinking has a preventive effect on cardiovascular diseases. Effects of alcohol drinking on lipid metabolism including an increase in HDL cholesterol concentration and a decrease in LDL cholesterol concentration are the main reasons for the anti-atherosclerotic action of alcohol.
View Article and Find Full Text PDFCureus
October 2024
Orthopaedic Surgery, Desert Orthopaedic Center, Las Vegas, USA.
Platelet-rich plasma (PRP) is an autologous blood product containing concentrated platelets, growth factors, and anti-inflammatory cytokines that promote healing and regeneration. Platelets release active components through a degranulation process, which is inhibited by certain nonsteroidal anti-inflammatory drugs (NSAIDs). Current deferral guidelines are not established, but NSAIDs are expected to have a time-dose relationship with platelet inhibition.
View Article and Find Full Text PDFMicrovasc Res
January 2025
Departamento de Farmacologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, SP, Brazil. Electronic address:
Bothrops asper venom (Bav) contains metalloproteinases that disrupt the microvascular system, impairing muscle tissue regeneration after injury. This study investigated the impact of the cyclooxygenase-2 (COX-2) pathway on vascular injury and revascularization in muscle injuries induced by Bav. Mice were injected with Bav into the gastrocnemius muscle and treated with lumiracoxib, a selective COX-2 inhibitor, 30 min, 2 days, and 6 days post-Bav injection.
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