Serotonin-induced contractility in human saphenous vein is inhibited by naftidrofuryl

Vascular endothelial denudation contributes to vasospasm by causing platelet aggregation und the subsequent releuse of vasoconstrictors such as serotonin. It has recently been suggested that naftidrofuryl fumarate (NFT) may oppose serotonin‐induced vasoconstriction. Fourteen rings of human saphenous vein from 14 patients undergoing varicose vein surgery were tested in standard organ bath experiments. Cumulative dose—response curves and maximal Contraction in response to serotonin were recorded and this was repeated in the presence of NFT at 10−6 and 10−3 mol/l. The difference in maximal contractility between the three sets of curves was significant (P < 0.0001). Sensitivity to serotonin in each of the three curues was meusured using the concentration for half‐maximal response; differences were again significant (P < 0.0001). It is concluded that NFT reduces serotonin‐induced contractility in a dose‐dependent fashion in rings of human saphenous vein in vitro. These results suggest a possible role for NFT in reducing vasospasm and support further investigation of this drug.