Search results for "Thromboxanes"

ABNORMALLY HIGH THROMBOXANE BIOSYNTHESIS IN HOMOZYGOUS HOMOCYSTINURIA. EVIDENCE FOR PLATELET INVOLVEMENT AND PROBUCOL-SENSITIVE MECHANISM.

1993

Homocystinuria due to homozygous cystathionine beta-synthase deficiency is an inborn error of metabolism characterized by a high incidence of thrombosis and premature atherosclerosis. We evaluated TXA2 biosynthesis in vivo and several in vitro tests of platelet function in 11 homocystinuric patients and 12 healthy controls. In vitro, patients' platelet aggregation was within control values as were TXB2 formation, fibrinogen binding, and ATP secretion in response to thrombin. In contrast, the urinary excretion of 11-dehydro-TXB2, a major enzymatic derivative of TXA2, was > 2 SD of controls in all patients (1,724 +/- 828 pg/mg creatinine, mean +/- SD, in patients vs. 345 +/- 136 in controls, …

The effect of two low doses of aspirin on whole blood thromboxane and prostacyclin generation in healthy subjects

1983

SummaryThe effects of two low doses of aspirin (20 mg and 100 mg) on prostacyclin and thromboxane formation during whole blood clotting were studied in 8 healthy volunteers.A single 100 mg aspirin dose caused more than 90% reduction of both serum TXB2 and 6-keto-PGF1α; a single 20 mg dose of aspirin inhibited serum TXB2 more than 6-keto-PGF1α but effects on these two products could not be completely dissociated.However, the effect of a single 20 mg aspirin dose on serum TXB2, was of much longer duration than its inhibitory effect on PGI2 synthesis during whole blood clotting.

Circulating immune complexes and platelet thromboxane synthesis in patients with insulin-dependent (type I) diabetes mellitus

1984

Platelets from diabetic subjects with circulating immune complexes (CIC) synthesized greater amounts of thromboxane than did platelets from CIC-negative patients or controls. In view of the known action of CIC on platelet function, a relationship between these two factors may be suggested in the initiation and progression of microangiopathy in diabetes.

Enhanced platelet thromboxane synthesis and reduced macrophage-dependent fibrinolytic activity related to oxidative stress in oral contraceptive-trea…

1996

Abstract In previous studies conducted in rats and in women, we have shown that oral contraceptive (OC) administration induced a platelet hyperaggregation simultaneously with an increased platelet lipid biosynthesis which might be related to lipid peroxidation. In the present study, we specifically studied the arachidonic acid and the fibrinolytic pathways in relation to the fatty acid composition in female rats treated for 6 weeks with OC (ethinyl estradiol plus lynestrenol). We found that platelets of treated animals were not only hyper-responsive to thrombin and ADP, but also to sodium arachidonate. In addition, the results of the thrombin-induced release of labeled arachidonic acid pre-…

Complement components in relation to macrophage function

1983

Determinants of enhanced thromboxane biosynthesis in renal transplantation

2001

Determinants of enhanced thromboxane biosynthesis in renal transplantation.BackgroundDespite great improvement in patient and graft survival, the long-term morbidity and mortality in renal transplant recipients (RTRs) are still significant, with a high incidence of cardiovascular disease-related deaths.MethodsWe investigated thromboxane (TXA2) biosynthesis and endothelial and coagulative activation in 65 patients who received a renal transplant.ResultsThe rate of TXA2 biosynthesis (urinary 11-dehydro-TXB2 excretion largely reflects platelet TXA2 production in vivo) was significantly (P < 0.0001) higher in RTRs than in healthy subjects. Plasma von Willebrand factor (vWF) and thrombin-antithr…

Different metabolic behavior of long-chain n-3 polyunsaturated fatty acids in human platelets.

1988

Abstract Whereas numerous studies deal with the effects and metabolism of eicosapentaenoic acid (20:5( n −3)) in platelets, very few concern docosahexaenoic acid (22:6( n −3)), although both acids are consumed in equal amounts from most fish fat. The present paper reports the modulation of 22:6( n −3) oxygenation as well as that of endogenous arachidonic acid (20:4( n −6)) in 22:6( n −3)-rich platelets. Like the oxygenation of 20:5( n −3), the lipoxygenation of 22:6( n −3) occurred at a low level when incubated alone, but was markedly increased in the presence of 20:4( n −6), suggesting a similar peroxide tone dependency. 20:5( n −3) could not replace 20:4( n −6) in the increasing 22:6( n −…