Prostanoid production in varicose veins: evidence for decreased prostacyclin with increased thromboxane A2 and prostaglandin E2 formation.

In this study, formation of arachidonic acid-derived prostanoids was investigated in saphenous veins of varicosed and nonvaricosed patients, all undergoing saphenectomy respectively for varicosis or in preparation for coronary bypass operation. Venous production of prostacyclin (PGI2), thromboxane A2 (TXA2) and prostaglandin E2 (PGE2) was assessed by bioassay and/or radioimmunologic assays as appropriate. Fragments of saphenous veins from varicosed patients produced significantly less PGI2 and more TXA2 and PGE2 than those from the control patients. Addition of arachidonic acid to incubation mixtures dose dependently increased release of these prostanoids, but the levels of PGI2 produced were consistently lower in veins from varicosed patients. No differences were found in varicosed patients between various segments of the same vein, no matter whether macroscopically affected or unaffected. These results demonstrate that the cyclooxygenase pathway in the venous wall of subjects with varicosis is shifted toward lesser formation of PGI2 and higher production of proaggregatory and proinflammatory prostanoids such as PGE2 and TXA2. These biochemical changes may be relevant to inflammation and thrombogenesis in varicosis.