DIFFERENCES BETWEEN UPPER AND LOWER-LIMBS IN VENOUS ENDOTHELIAL REACTIVITY IN HUMANS

Objective: To determine the variability of endothelial reactivity to v enostasis in the upper and lower Limbs of healthy subjects. Participan ts: Ten healthy volunteers were investigated twice, at an interval of 1-week. Main outcome measures: Plasma concentrations of substances rel eased from endothelial cells were determined in each limb after 10 min of venostasis in a sequential manner. Tissue plasminogen activator (t PA), plasminogen activator inhibiting factor (PAI-1), thrombin-antithr ombin complexes (TAT) and D-dimers (D-Di) were used as indicators of t he thrombotic process and its reactions; angiotensin converting enzyme (ACE) and endothelin-1 (ET1) were related to endothelial cell activit y involved in vascular tone regulation. Results: No difference was obs erved in endothelial cell recovery following venostasis after an inter val of 1 week. A significant difference in endothelial cell release wa s found between the upper and lower limbs and between the right and le ft legs. Conclusions: Excellent reproducibility of measurements was ob served. In keeping with the higher frequency of venous thrombosis in t he lower limbs, the left leg seemed to be less reactive after venostas is, and the endothelium was more reactive in the upper than in the low er limbs.