There is a growing number of contradictory reports indicating that adenosine diphosphate (ADP) can be a useful agonist in monitoring of the antiplatelet action of acetylsalicylic acid (ASA) in humans and animals. In the current study, we aimed to determine the conditions for using ADP to trigger platelet aggregation in order to detect ASA-mediated inhibition of rat platelet reactivity. Initiall...

The initial inventory of platelet aggregation inhibitors (1) dealt with those isolated from snake venoms. This updated inventory includes in addition to several new inhibitors platelet aggregation from snake venoms, those that were isolated from other animal sources. They are proteins or glycoproteins with their molecular weight ranging from 5000 to several tens of thousands. These factors inhi...

This study characterizes a congenital hemorrhagic disorder caused by a platelet function defect with the following features: (1) severely impaired platelet aggregation and fibrinogen or von Willebrand factor (vWF) binding induced by adenosine diphosphate (ADP); (2) defective aggregation, release reaction, and fibrinogen or vWF binding induced by other agonists; (3) normal aggregation and releas...

BACKGROUND The antiplatelet effect of aspirin is attributed to platelet cyclooxygenase-1 inhibition. Controversy exists on the prevalence of platelet resistance to aspirin in patients with coronary artery disease and effects of aspirin dose on inhibition. Our primary aim was to determine the degree of platelet aspirin responsiveness in patients, as measured by commonly used methods, and to stud...

When tobacco is smoked, chewed or snuffed, nicotine is absorbed by the lungs or mucous membrane and quickly moved into the bloodstream, where it is circulated throughout the brain. In fact nicotine is highly dangerous to be consumed in any form. The present study was conducted to know the adverse effects of nicotine on the platelet aggregation in cerebral microvessels of mice. Male mice of aver...

To study the resistance to standard dosage of clopidogrel among Iranian patients following percutaneous coronary intervention measured by platelet aggregation test.Patients undergoing percutaneous coronary intervention in Imam Hussein Medical center, Tehran, Iran, who were under treatment with aspirin, but had no history of clopidogrel usage, entered the study. Patients received standard dosage...

To study the resistance to standard dosage of clopidogrel among Iranian patients following percutaneous coronary intervention measured by platelet aggregation test.Patients undergoing percutaneous coronary intervention in Imam Hussein Medical center, Tehran, Iran, who were under treatment with aspirin, but had no history of clopidogrel usage, entered the study. Patients received standard dosage...

This study was conducted to assess the feasibility of COX1 NSAID substitution for aspirin for preventative therapy related to circulating anticoagulants, as manifest by inhibition of platelet aggregation. There was no difference in platelet aggregation inhibition between aspirin, naproxen, ketoprofen or diclofenac and misoprostol (in combination in the form of Arthrotec). As COX1 NSAIDs appear ...

Collagen activates platelets by transducing signals through glycoprotein VI (GPVI). It is not clear whether collagen can directly activate fibrinogen receptors on the adherent platelets without a role for positive feedback agonists. We investigated the contribution of secondary G protein signaling to the mechanism of GPVI-stimulated platelet aggregation using the GPVI-selective agonists, convul...

OBJECTIVES Thromboelastography Platelet Mapping (TEGPM) is an assay designed to detect platelet inhibition due to aspirin or clopidogrel-like drugs. The purpose of this study was to evaluate potential causes of error in the design or operation of the assay. METHODS We evaluated percent inhibition of platelets due to aspirin or clopidogrel using TEGPM, which measures clot viscoelastic maximum ...