PLASMA ENDOTHELIN-1 RELEASE IN NORMAL AND VARICOSE SAPHENOUS VEINS

The aim of the study was to investigate the release of endothelin-1 (E T-1) in normal and varicose saphenous veins at baseline and after veno us stasis test. Ten patients (eight women and two men, mean age 43 +/- 4) with primarily varicose great saphenous veins and ten controls (eig ht women and two men, mean age 42 +/-6) were recruited. After 30 minut es of resting in supine position, venous occlusion in a leg was perfor med with a sphygmomanometer provided to keep the pressure in the cuff intermediate between systolic and diastolic blood pressure for 10 minu tes. Blood samples were taken from the great saphenous vein just above the medial malleolus at baseline and 10 minutes after venous stasis w as begun. Plasma ET-1 was determined by a radioimmunoassay system. Res ults are expressed as mean +/-SD. Plasma ET-1 concentration was higher in varicose than in normal saphenous veins (4 +/-0.1 pmol/L vs 2.6 +/ -0.1 pmol/L, P<0.001), and it significantly increased (P<0.001) in bot h groups after venous stasis when compared with baseline (6.8 +/-0.9 p mol/L and 3.6 +/-0.1 pmol/L in varicose and normal saphenous veins, re spectively). Absolute increase in plasma ET-1 was significantly greate r in varicose than in normal saphenous veins (2.8 +/-0.9 pmol/L vs 1.0 +/-0.2 pmol/L, P<0.01). In conclusion, increased local ET-1 release i n varicose saphenous veins could be a marker for venous endothelial ac tivation/damage and/or contribute to promote the morphologic alteratio ns of the varicose vein wall by stimulating smooth muscle cell prolife ration. On the other hand, increased ET-1 release could contribute to counterbalancing the varicose venous relaxation and to increasing prel oad in varicose patients via ET-1-induced venoconstriction.