Pyridoxal-5'-phosphate (PLP) the coenzyme form of vitamin Bg. has been shown to inhibit platelet aggegation [l-31 but the mechanism of its inhibitory action remains to be elucidated. Because of its negative charge and hydrophilic nature PLP does not cross the cell membrane and has been used as a probe for several membrane systems [3]. Since PLP inhibits platelet activation induced by a variety ...

We have used two murine monoclonal antibodies, each directed against one component of the human platelet membrane glycoprotein (GP) IIb-IIIa complex, to examine further the molecular requirements for fibrinogen binding to the platelet surface and subsequent platelet-platelet cohesion (aggregation). Although neither AP3, which is directed against GPIIIa, nor Tab, which is specific for GPIIb, wer...

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...

Platelets promote angiogenesis by releasing angiogenesisregulating factors from their a-granules upon aggregation. This effect has both physiologic and pathologic significance as it may contribute to carcinogenesis. Platelet a-granule release and aggregation are regulated, in part, via protein kinase C (PKC) a and b signaling. Our study investigated the effects of PKC inhibition on aggregation,...

We examined the role of microtubules in platelet aggregation and secretion (release reaction) induced by the calcium ionophore A23187 (0.8-5 muM). At these concentrations, platelet aggregation was preceded by a lag period of approximately 1 min. Colchicine (an agent that disrupts microtubule assembly-disassembly) was shown to bind to platelet microtubules by employing [(3)H]colchicine at a conc...

BACKGROUND We investigated whether luminal release of nitric oxide (NO) contributes to inhibition of platelet activation and whether these effects are reduced in patients with atherosclerosis. METHODS AND RESULTS Femoral blood flow velocity and ex vivo whole blood platelet aggregation by impedance aggregometry were measured in femoral venous blood during femoral arterial infusion of acetylcho...

Platelets promote angiogenesis by releasing angiogenesisregulating factors from their a-granules upon aggregation. This effect has both physiologic and pathologic significance as it may contribute to carcinogenesis. Platelet a-granule release and aggregation are regulated, in part, via protein kinase C (PKC) a and b signaling. Our study investigated the effects of PKC inhibition on aggregation,...

A novel series of platelet receptor glycoprotein (Gp) IIb/IIIa antagonists with condensed heterocycles as their basic core was synthesized. In an in vitro assay, trans-4-(5-amidinobenzofuran-2-carboxamido)cyclohexyloxyacetic+ ++ acid 17e and trans-3-[4-(5-amidinobenzofuran-2- carboxamido)cyclohexyl]propionic acid 17f produced marked inhibitions with IC50 values of 0.018 and 0.006 microM, respec...

Platelets promote angiogenesis by releasing angiogenesis-regulating factors from their α-granules upon aggregation. This effect has both physiologic and pathologic significance as it may contribute to carcinogenesis. Platelet α-granule release and aggregation are regulated, in part, via protein kinase C (PKC) α and β signaling. Our study investigated the effects of PKC inhibition on aggregation...

BACKGROUND AND OBJECTIVES P-selectin ctin has been implicated in important platelet functions. However, neither its role in thrombus formation and cardiovascular disorders nor its suitability as a therapeutic target structure is entirely clear. DESIGN AND METHODS Platelet aggregation was assessed in complementary in vitro settings by measurements of static aggregation, standardized aggregomet...