Diosmin therapy alters the in vitro metabolism of noradrenaline by the varicose human saphenous vein.

We have previously shown that diosmin 30-100 mumol/l reduces the metabolism of noradrenaline (NA) in fragments of varicose saphenous veins obtained at surgery. Since diosmin is widely used in patients with chronic venous insufficiency we decided to test if the drug, administered in therapeutic doses to patients, would affect NA metabolism in the veins of the individuals so treated. Sex- and age-matched patients in which surgery was indicated were allocated in the order of admission to control (n = 5) or treated groups (n = 6; 600 mg twice a day, orally, during 10 days). Fragments of saphenous vein were incubated with [3H]NA 0.2 mumol/l during 60 min; the interval between operation and incubation was less than 30 min. Column chromatography and liquid scintillation counting were used to measure [3H]NA and its metabolites. In the treated group, accumulation of [3H]NA was significantly reduced and the formation of metabolites approximately halved. The present results show that oral administration of diosmin has evident effects on the in vitro metabolism of noradrenaline by the varicose tissue.