Increased ability of tirofiban to maintain its inhibitory effects on the binding of fibrinogen to platelets in blood from patients with and without diabetes mellitus
| Autor: | Deborah A. Whitaker, Burton E. Sobel, David J. Schneider, Friederike K. Keating, Patricia Q. Baumann |
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| Rok vydání: | 2005 |
| Předmět: |
Male
medicine.medical_specialty Platelet Glycoprotein GPIIb-IIIa Complex In Vitro Techniques Fibrinogen chemistry.chemical_compound Internal medicine Diabetes Mellitus Medicine Humans Platelet Platelet activation Aged business.industry General Medicine Tirofiban Flow Cytometry Platelet Activation Adenosine diphosphate Endocrinology chemistry Eptifibatide Platelet aggregation inhibitor Tyrosine Female Cardiology and Cardiovascular Medicine business Glycoprotein IIb/IIIa Platelet Aggregation Inhibitors medicine.drug |
| Zdroj: | Coronary artery disease. 17(1) |
| ISSN: | 0954-6928 |
| Popis: | OBJECTIVES: Both tirofiban and eptifibatide release rapidly from glycoprotein IIb-IIIa but have different dissociation constants (KD of tirofiban=15 nmol/l, of eptifibatide=120 nmol/l). Binding of fibrinogen to glycoprotein IIb-IIIa is biphasic, forming an initial reversible complex (KD=155-180 nmol/l) and a second more stable complex (KD=20-70 nmol/l). Diabetes is known to alter platelet function. To determine the influence of affinity on inhibitory effects in blood from patients with (n=20) and without (n=20) diabetes mellitus, we characterized the extent of inhibition as a function of time. METHODS: Blood was added to reaction tubes containing tirofiban 100 ng/ml or eptifibatide 1.7 microg/ml (concentrations previously defined to be optimal) plus a platelet agonist (1 micromol/l adenosine diphosphate or 25 micromol/l thrombin receptor agonist peptide), and fluorochrome-labeled fibrinogen before analysis by flow cytometry. RESULTS: The extent of inhibition early on (30 s to 3 min) was similar (>85%) with either agent in blood from those with and without diabetes mellitus, whereas the extent of inhibition 10-15 min later was maintained more effectively with tirofiban than with eptifibatide (difference in slope P |
| Databáze: | OpenAIRE |
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