Endothelium-Derived Relaxing Factor Release from Normal and Varicose Human Saphenous Veins

Abstract

Objective:

To evaluate the role of endothelium-derived relaxing factor (EDRF) in the regulation of smooth muscle tone in normal and varicose human saphenous veins.

Design:

An in vitro study of site-matched saphenous vein samples from patients undergoing varicose vein surgery or carotid endarterectomy.

Setting:

Department of Surgery, University of Leicester, Leicester Royal Infirmary.

Patients:

Nine patients undergoing varicose vein surgery and seven patients undergoing carotid endarterectomy.

Measurements:

Vein samples were contracted with noradrenaline and relaxation studies performed with acetylcholine (endothelium-dependent) and sodium nitroprusside (endothelium-independent).

Results:

There was no statistical difference in either smooth muscle contraction in response to noradrenaline or in endothelial-dependent relaxation in response to acetylcholine. All veins retained the ability to relax in response to nitroprusside.

Conclusions:

No evidence of a defect in either smooth muscle function or EDRF release has been found that may contribute to the aetiology of varicose veins.