The thromboxane A2 pathway plays a major role in governing the reactions involved in both the inflammatory and hemostatic biological mechanisms. Cyclooxygenases 1 & 2 act to convert arachidonic acid to thromboxane A2. Scientific studies report cyclooxygenase-2 is up-regulated in many different chronic disease states as well as in chronic inflammation. This explains one major causes of residual thromboxane risk, “aspirin resistance.” Levels of urinary 11-dehydrothromboxane B2 reflect activity of components of the thromboxane A2 pathway that result n thromboxane A2 generation. The assay is normalized to the patient’s urine creatinine concentration and is non-invasive and normalized utilizing standard controls.

Effects of smoking cessation and nicotine substitution on systemic eicosanoid production in man

"This study investigated the effects of smoking cessation with and without nicotine substitution on the excretion of major urinary metabolites of thromboxane A2 and prostacyclin; 11-dehydrothromboxane B2 and 2, 3-dinor-6ketoprostaglandin F1 alpha, respectively, as well as on the excretion of leukotriene E4 in man."

"The fact that eicosanoid production remains at pre-cessation levels in volunteers who quit smoking but use nicotine substitution may be involved in the risk of cardiovascular complications reported during nicotine replacement therapy."

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Risk factors for carotid atherosclerosis and platelet activation

"In the 24 patients in whom the plaque score was measured, multivariate analysis indicated a significant positive correlation between urinary excretion of 11-dehydrothromboxane B2 and plaque score, age, smoking and hypercholestermia.  Our results indicate the risk factors such as age, hypercholestermia, atherosclerosis and smoking activate platelets in vivo to develop carotid atherosclerosis."

"Multivariate analysis indicated a significant positive correlation between urinary excretion of 11-dehydrothromboxane B2 and plaque score, age, smoking and hypercholesteremia."

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Nicotine effects on eicosanoid formation and hemostatic function: comparison of transdermal nicotine and cigarette smoking

“Cigarette smoking increased the urinary excretion of 11-dehydrothromboxane B2 (reflecting thromboxane A2 generation).”

“Cigarette smoking was also associated with higher levels of fibrinogen in plasma.”

“Cigarette smoking and transdermal nicotine treatment were both associated with a higher white blood cell count compared with the placebo patch.”

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Reduction of thromboxane A2 synthesis in pregnancy by polyunsaturated fatty acid supplements

"High-dose supplements of fish oil reduce thromboxane synthesis in nonpregnant human subjects and were therefore proposed as a means of preventing various small-vessel disorders, including preeclampsia.  The effect of fish oil on thromboxane metabolism in pregnancy was investigated in our study."

"A decrease ranging from 32% to 71%, in 24-hour urinary 11-dehydro-thromboxane B2 excretion (mean reduction from 1606 pg/mg creatinine to 779 pg/mg creatinine, p < 0.001) was found among the 11 fish oil-treated women. No change in excretion was found among the control women. No maternal, fetal, or neonatal bleeding disturbances occurred, and no laboratory changes in coagulation markers were observed.”

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