Search results for "iloprost"
showing 10 items of 22 documents
Temporal quantitative phosphoproteomics of ADP stimulation reveals novel central nodes in platelet activation and inhibition
2017
Adenosine diphosphate (ADP) enhances platelet activation by virtually any other stimulant to complete aggregation. It binds specifically to the G-protein-coupled membrane receptors P2Y1 and P2Y12, stimulating intracellular signaling cascades, leading to integrin aIIbb3 activation, a process antagonized by endothelial prostacyclin. P2Y12 inhibitors are among the most successful antiplatelet drugs, however, show remarkable variability in efficacy. We reasoned whether a more detailed molecular understanding of ADP-induced protein phosphorylation could identify (1) critical hubs in platelet signaling toward aggregation and (2) novel molecular targets for antiplatelet treatment strategies. We ap…
Antiplatelet effects of intravenous iloprost in patients with peripheral arterial obliterative disease
1986
The dose-dependent inhibition of platelet aggregation by the chemically stable, prostacyclin-mimetic, iloprost, was studied in patients suffering from stage II-III peripheral arterial obliterative disease (PAOD). The study was designed as a randomized placebo-controlled cross-over trial. Iloprost was administered i.v. to six patients at doses of 0.5, 1.0, 2.0 or 3.0 ng/kg X min for 4 h, with an interval of 2-3 days between the infusions. During iloprost infusion, systolic and diastolic arterial blood pressure, heart rate and blood flow in the affected limb remained unchanged. In contrast, there was a considerable, dose-dependent inhibition of ADP- and thrombin-induced platelet aggregation a…
Iloprost treatment in patients with Raynaud's phenomenon secondary to systemic sclerosis and the quality of life: a new therapeutic protocol
2006
Objectives: to evaluate the clinical efficacy and the effects on the quality of life of Iloprost, a prostacyclin analogue, used, according to a new protocol, in patients with Raynaud’s phenomenon secondary to Systemic Sclerosis. Methods: in this randomized study we treated 30 patients with Iloprost given by intravenous infusion, at progressively increasing doses (starting from 0.5 ng/Kg/min up 2 ng/Kg/min) over a period of 6 hours a day for ten days in two consecutive weeks, with repeated cycles at regular intervals of three months for 18 months. The results were compared with those obtained in 30 other patients, who had received the same drug but with different posologic schemes. Results: …
In vitro Analysis of Synergistic Effects of Fibrinolytic Agents and Prostacyclin Analogues
1997
We investigated the in vitro thrombolytic effects of streptoki-nase, urokinase, alteplase and saruplase, alone or in combination, with the prostacyclin analogues, iloprost and taprostene. Human platelet-rich plasma was stimulated with collagen (1 μg/ml) to generate thrombi containing platelets and fibrin. Following treatment with fibrinolytic agents, lysis was allowed to proceed for 30 min and was then terminated with aprotinin (2,000 ClU/ml). To evaluate the combinatory effects of fibrinolytic agents and prostacyclin analogues, we used concentrations of fibrinolytic agents which reduced thrombi weight by less than 50%. Neither iloprost nor taprostene alone demonstrated any thrombolytic eff…
Prostacyclin receptor desensitization is a reversible phenomenon in human platelets.
1997
Background Long-term exposure of platelets to endogenous or exogenous prostacyclin or its analogues might result in desensitization of the platelet prostacyclin receptor in vitro and in vivo accompanied by a loss in receptor density on the platelet surface and a reduced sensitivity toward the inhibitory effects of prostacyclins. However, the reversibility of this process in platelets has not yet been investigated. Methods and Results Human platelets desensitized by the chemically stable prostacyclin analogue iloprost showed a significant reduction in [ 3 H]-iloprost binding sites that was reversed by saponin permeabilization. This indicates functionally active internalized prostacyclin rec…
Time-resolved characterization of cAMP/PKA-dependent signaling reveals that platelet inhibition is a concerted process involving multiple signaling p…
2014
One of the most important physiological platelet inhibitors is endothelium-derived prostacyclin which stimulates the platelet cyclic adenosine monophosphate/protein kinase A (cAMP/PKA)-signaling cascade and inhibits virtually all platelet-activating key mechanisms. Using quantitative mass spectrometry, we analyzed time-resolved phosphorylation patterns in human platelets after treatment with iloprost, a stable prostacyclin analog, for 0, 10, 30, and 60 seconds to characterize key mediators of platelet inhibition and activation in 3 independent biological replicates. We quantified over 2700 different phosphorylated peptides of which 360 were significantly regulated upon stimulation. This com…
Deciphering of ADP-induced, phosphotyrosine-dependent signaling networks in human platelets by Src-homology 2 region (SH2)-profiling.
2012
Tyrosine phosphorylation plays a central role in signal transduction controlling many important biological processes. In platelets, the activity of several signaling proteins is controlled by tyrosine phosphorylation ensuring proper platelet activation and aggregation essential for regulation of the delicate balance between bleeding and hemostasis. Here, we applied Src-homology 2 region (SH2)-profiling for deciphering of the phosphotyrosine state of human platelets activated by adenosine diphosphate (ADP). Applying a panel of 31 SH2-domains, rapid and complex regulation of the phosphotyrosine state of platelets was observed after ADP stimulation. Specific inhibition of platelet P2Y receptor…
Synergistic interaction of adenylate cyclase activators and nitric oxide donor SIN-1 on platelet cyclic AMP
1995
Abstract The molecular mechanism of the synergistic platelet inhibition by activators of adenylate cyclase and guanylate cyclase in human platelets was investigated. The adenylate cyclase activators iloprost and prostaglandin E 1 and the guanylate cyclase activator 3-morpholino-synonimine (SIN-1) dose-dependently inhibited thrombin-induced aggregation of washed human platelets. Furthermore, SIN-1 at a concentration inhibiting platelet aggregation by only 10% shifted the IC 50 values of iloprost and prostaglandin E 1 by one order of magnitude to the left, indicating a synergistic action of adenylate cyclase and guanylate cyclase activators. Iloprost and prostaglandin E 1 dose-dependently ele…
Increased Platelet Sensitivity toward Platelet Inhibitors during Physical Exercise in Patients with Coronary Artery Disease
1999
Generalized atherosclerosis and coronary artery disease (CAD) are associated with endothelial dysfunction and during acute myocardial ischemia platelet activation has been reported. Activated platelets exert activated fibrinogen receptors (GP IIb/IIIa) and express CD 62p being regarded as reliable marker for platelet activation. Patients with angiographically proven CAD performed a bicycle exercise test until the onset of angina or ST-segment depression. We studied the ischemia-induced alterations in fibrinogen binding to activated platelet GP IIb/IIIa receptors and CD 62p expression. Therefore, the basal fibrinogen binding to GP IIb/IIIa and CD 62p expression and the thrombin-concentration…
SICUREZZA E TOLLERABILITA' DEL TRATTAMENTO LOCALE CON ILOPROST IN PAZIENTI AFFETTI DA MALATTIA DI LA PEYRONIE. STUDIO PILOTA DI FASE 1 E PROPOSTA DI …
2010
Purpose. Intralesional therapy is a less invasive method for the treatment of Peyronie's disease. The objective of this study was to evaluate safety and tolerability of intralesional injections of Iloprost (I2 Prostacyclin analogue) for its property to suppress in fibroblasts CTFG (Connective tissue growth factor) production, which acts in concert with TGF-ß to stimulate the fibrotic process.?Methods. Nineteen patients with Peyronie's disease were preliminarily evaluated by considering the degree of penile curvature, plaque size and local and systemic symptoms. Each patient then received weekly intralesional injections of 200ng of Iloprost in 1 ml of normal saline for 4-5 weeks. If tolerate…