thromboxane-b2 and Peripheral-Vascular-Diseases

Peripheral artery angiography, a common diagnostic procedure, may cause early and late adverse reactions, such as anaphylaxis, thrombosis and possible progression of the underlying arterial disease. To test the hypothesis that radiographic contrast medium may contribute to these events by adversely affecting the endothelium, leucocytes and/or platelets, 19 subjects undergoing angiography for the investigation and/or treatment of lower limb atherosclerosis were recruited. Blood was obtained from the external iliac vein before, and at serial intervals after, the injection of radiographic contrast medium into the ipsilateral femoral artery for diagnostic use. Markers of endothelial cell injury (von Willebrand factor (vWf)), platelet activation (soluble P-selectin) and leucocyte activation (neutrophil elastase and soluble L-selectin) were measured in citrated plasma. Soluble intercellular adhesion molecule-1 (sICAM-1) and thromboxane B(2), which are non-specific markers of inflammation, were also measured. Compared with the sample prior to angiography, levels of soluble L-selectin and sICAM-1 were reduced (p<0.02) immediately after passage of the last bolus of contrast medium. 15 min later, levels returned to normal but the level of vWf had increased (p<0.02). After 30 min, only levels of thromboxane B(2) were increased (p<0.05). The following day both vWf (p<0.01) and soluble P-selectin (p<0.05) were increased. These data point to both early and late effects of contrast medium on markers of endothelial, platelet and leucocyte function.

Topics: Aged; Arteriosclerosis; Biomarkers; Blood Platelets; Contrast Media; Endothelium, Vascular; Female; Humans; Intercellular Adhesion Molecule-1; Iohexol; Leg; Leukocytes; Male; Middle Aged; P-Selectin; Pancreatic Elastase; Peripheral Vascular Diseases; Radiography; Thromboxane B2; von Willebrand Factor

To assess the effects of picotamide, an antithromboxane receptor and antithromboxane synthase drug, on vascular function and endothelin-1 release, 20 patients with peripheral arterial disease, without hypertension or diabetes mellitus, receiving placebo and picotamide (900 mg/day) were studied. The modifications of vascular parameters were evaluated by arterial distensibility index and postischemic hyperemia test (postischemic perfusion index and recovery time). Endothelin-1, prostacycline, and thromboxane B2 were determined under resting conditions and after treadmill test. Picotamide treatment caused a decrease of resting thromboxane B2 and endothelin-1 concentrations, produced an improvement of the vascular function as seen by the increase of vascular parameters reported, and attenuated the ischemic treadmill-induced increase of thromboxane B2, but not of endothelin-1. These data confirm that the picotamide improved vascular flow by the reduction of thromboxane-mediated effects, reduced resting endothelin-1 levels, but did not attenuate endothelin-1 concentrations induced by the treadmill stress.

Topics: Aged; Endothelin-1; Exercise Test; Female; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Phthalic Acids; Platelet Aggregation Inhibitors; Prostaglandins F; Thromboxane B2; Vasomotor System

Chloroquine is known to inhibit platelet activation by various mechanisms including arachidonic acid liberation from membrane phospholipids. We therefore examined the influence of chloroquine in addition to the conventional EDTA/acetylsalicylic acid cocktail on thromboxane B2-plasma values. In 11 healthy volunteers the influence of venous occlusion, needle diameter and EDTA (+ acetylsalicylic acid + chloroquine) was examined. In 27 healthy adults, 51 patients with clinically manifested coronary heart disease as well as in 31 patients with peripheral vascular disease parallel samples drawn in the presence of chloroquine showed lower thromboxane B2 in all these three groups of patients, especially in conditions associated with platelet activation and high thromboxane B2-values. These findings suggest that the routine addition of 10 mM chloroquine to the conventional stabilization cocktail can strongly be recommended.

Topics: Adult; Aged; Artifacts; Chloroquine; Coronary Disease; Female; Humans; Male; Middle Aged; Peripheral Vascular Diseases; Radioimmunoassay; Reproducibility of Results; Sensitivity and Specificity; Specimen Handling; Thromboxane B2

Peripheral vascular disease (PVD) is an indicator of diffuse atherosclerosis and is associated with a greatly increased incidence of coronary heart and cerebrovascular disease. Although several studies have assessed whether in vivo platelet activation takes place in patients with PVD, no data are available comparing different platelet function tests in this patient population. We have compared prospectively four tests for the measurement of in vivo platelet activation (plasma betaTG, plasma PF4, intraplatelet betaTG and urinary excretion of 11-dehydro-TXB2) and one in vitro platelet function test (ADP-induced platelet aggregation) in 63 well-characterized patients with intermittent claudication and in 18 age- and sex-matched healthy volunteers. No statistically significant difference was found between patients and controls for plasma betaTG (20.0 +/- 11.8 vs. 18.8 +/- 9.0 ng/ml, respectively), plasma PF4 (5.2 +/- 2.9 vs. 6.3 +/- 3.5 ng/ml), betaTG/PF4 ratio (4.0 +/- 2.9 vs. 3.6 +/- 1.8), intraplatelet betaTG (4503 +/- 1482 vs. 4059 +/- 1065 ng/ml), and threshold aggregatory concentration of ADP (1.7 +/- 0.72 vs. 1.45 +/- 0.56 microM). Urinary 11-dehydro-TXB2 was instead significantly higher in the PVD group (55.4 +/- 27.5 vs. 26.7 +/- 7.0 ng/h, p <0.001). Our study shows that urinary 11-dehydro-TXB2 is a more sensitive index of in vivo platelet activation than the measurement of either platelet specific proteins or of in vitro platelet aggregation in patients with PVD.

Topics: Adenosine Diphosphate; Adult; Aged; beta-Thromboglobulin; Biomarkers; Cross-Sectional Studies; Female; Humans; Leg; Male; Middle Aged; Peripheral Vascular Diseases; Platelet Activation; Platelet Aggregation; Platelet Factor 4; Platelet Function Tests; Prospective Studies; Thromboxane B2

Topics: Adult; Arachidonic Acid; Blood Platelets; Chromatography, Thin Layer; Double-Blind Method; Fatty Acids, Omega-3; Female; Humans; Male; Malondialdehyde; Peripheral Vascular Diseases; Platelet Aggregation; Prostaglandins; Thromboxane B2