There is considerable evidence that platelet activation occurs in allergic airways diseases. In this study we aimed to investigate platelet adhesion to immobilized fibrinogen and intracellular calcium levels in a rat model of allergic inflammation. Male Wistar rats were challenged with ovalbumin (OVA). At 30 min to 24h after OVA-challenge, assays of platelet adhesion to immobilized fibrinogen and intracellular calcium levels using fura 2-AM loaded platelets were performed. The serum levels of IgE were approximately 5-fold greater in OVA-sensitized rats. A marked eosinophil influx in bronchoalveolar lavage (BAL) fluid of OVA-challenged rats at 24h after OVA-challenge was also seen. OVA-challenge resulted in a marked thrombocytopenia, as observed within 12h after OVA-challenge. The agonists ADP (0.5-50 microM) and thrombin (30-100 mU/ml) concentration-dependently increased platelet adhesion to immobilized fibrinogen. At an early time after OVA-challenge (30 min), platelets exhibited greater platelet adhesion compared with the non-sensitized group, whereas at a late time (24h) they exhibited lower platelet adhesion to both agonists. Moreover, at 30 min after OVA-challenge, intracellular calcium levels to ADP (20 microM) and thrombin (100 mU/ml)-activated platelets were greater compared with non-challenged rats. As opposed, at 24h after OVA challenge, a lower intracellular calcium level to ADP- and thrombin-activated platelets was observed. In conclusion, OVA-challenge in rats promotes a biphasic response in platelet adhesion consisting of an increased adhesion and intracellular calcium levels at an early phase (30 min), which progress to a reduction in adhesion and intracellular calcium levels at a late time (24h) after antigen challenge.
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http://dx.doi.org/10.1016/j.pupt.2010.03.006 | DOI Listing |
Langmuir
January 2025
Department of Biomedical Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States.
Blood-bearing medical devices are essential for the delivery of critical care medicine and are often required to function for weeks to months. However, thrombus formation on their surfaces can lead to reduced device function and failure and expose patients to systemic thrombosis risks. While clinical anticoagulants reduce device related thrombosis, they also increase patient bleeding risk.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Nanotechnology Research Center, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran 1416634793, Iran; Wound Care Solution, Nano Fanavaran Narin Teb Co., Tehran, P.O. Box 19177-53531, Iran; Physical Chemistry I, Department of Chemistry and Biology & Research Center of Micro and Nanochemistry and Engineering (Cμ), University of Siegen, 57076 Siegen, Germany. Electronic address:
This study reports the development of a highly absorbent Chitosan (CS)/Tannic Acid (TA) sponge, synthesized via chemical cross-linking with Epichlorohydrin (ECH) and integrated with zinc oxide nanoparticles (ZnO NPs) as a novel hemostatic anti-infection agent. The chemical properties of the sponges were characterized using Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and zeta potential measurements. Morphological and elemental analyses conducted through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDAX) revealed a uniform distribution of ZnO NPs, with particle sizes below 20 nm.
View Article and Find Full Text PDFBlood
January 2025
Medical University of Vienna, Vienna, Austria.
In thrombosis and hemostasis, the formation of a platelet-fibrin thrombus or clot is a highly controlled process that varies, depending on the pathological context. Major signaling pathways in platelets are well established. However, studies with genetically modified mice have identified the contribution of hundreds of additional platelet-expressed proteins in arterial thrombus formation and bleeding.
View Article and Find Full Text PDFFront Biosci (Landmark Ed)
January 2025
Department of Cardiology, The Second Affiliated Hospital of Chongqing Medical University, 401336 Chongqing, China.
Background: Myocardial ischemia-reperfusion (I/R) injury and coronary microcirculation dysfunction (CMD) are observed in patients with myocardial infarction after vascular recanalization. The antianginal drug trimetazidine has been demonstrated to exert a protective effect in myocardial ischemia-reperfusion injury.
Objectives: This study aimed to investigate the role of trimetazidine in endothelial cell dysfunction caused by myocardial I/R injury and thus improve coronary microcirculation.
Sensors (Basel)
January 2025
School of Biomedical Engineering, University of Technology Sydney, Sydney, NSW 2007, Australia.
Platelet cells are essential to maintain haemostasis and play a critical role in thrombosis. They swiftly respond to vascular injury by adhering to damaged vessel surfaces, activating signalling pathways, and aggregating with each other to control bleeding. This dynamic process of platelet activation is intricately coordinated, spanning from membrane receptor maturation to intracellular interactions to whole-cell responses.
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