Purpose: To investigate if noradrenaline (NA) and 5-hydroxyptamine (5-HT) drugs induce responses of isolated control and varicose veins are altered by removal of the endothelium. SUBJECTS #ENTITYSTARTX00026;
Methods: Specimens of the great saphenous vein (GSV) were obtained from 12 subjects with primary varicose veins and 12 subjects from donor vessels at cardiac surgery. A total of 10 normal healthy volunteers were selected for comparison. The diameter changes of GSV during the resting phase, at the end of 5 minutes occlusion, and then every 30 seconds post deflation for five minutes were measured using B-mode ultrasound. Post-surgery the vein sample was collected in a tube of Krebs-Henseleit solution.
Results: The repeated measure ANOVA test for the diameter, percent, and difference changes of GSV diameter from maximum diameter at different time intervals showed significance difference within and between all groups. NA and 5-HT produced concentration-dependent contractions of control and varicose saphenous vein segments. There was no significant difference in the potency of NA and for 5-HT, but the maximum response, normalized for tissue weight, was less in varicose vein segments. Removal of the endothelium had no effect on the potency of NA or 5-HT but significantly (p<0.05) reduced the maximum response to NA and 5-HT in varicose vein segments but not to 5-HT in control veins.
Conclusion: The venous endothelial damage may cause vascular smooth muscle contractions dysfunction that favours dilatation and secondary valvular insufficiency.
Keywords: 5-hydroxyptamine; Primary varicose veins; chronic venous insufficiency; in vitro vein study; in vivo vein study; noradrenaline.