Prostanoid Production in Varicose Veins: Evidence for Decreased Prostacyclin with Increased Thromboxane A2 and Prostaglandin E2 Formation

Abstract

In this study, formation of arachidonic acid-derived prostanoids was investi gated 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 (PGI ₂), thromboxane A₂ (TXA₂) and prostaglandin E ₂ (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 de pendently increased release of these prostanoids, but the levels of PGI₂ pro duced 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 demon strate that the cyclooxygenase pathway in the venous wall of subjects with vari cosis 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 thrombogene sis in varicosis.