Effect of preexcisional heparin anticoagulation on excised canine vein and artery prostanoid production.

The effect of heparin, administered prior to vessel dissection and excision, on the luminal release of prostanoids from an excised vessel was assessed. Eight adult mongrel dogs underwent removal of the jugular vein and carotid artery on one side, followed by intravenous administration of heparin sodium (150 IU/kg) and subsequent removal of these same vessels from the contralateral neck. The excised vessels were perfused in an ex vivo system with Hanks' balanced salt solution for five consecutive 15-min periods. Prostacyclin release (measured as 6-keto-PGF1 alpha) and thromboxane A2 (measured as thromboxane B2) release into the perfusate were quantitated by radioimmunoassay. Vessel segments were studied with and without first period thrombin stimulation (2 U/ml) and with arachidonic acid (4 micrograms/ml) stimulation during the last perfusion period. Vein segments following heparin administration exhibited greater prostacyclin production than veins not exposed to heparin. This effect did not occur in arteries. Heparin did not influence thromboxane A2 release. Luminal endothelial cell coverage was not affected by the presence or absence of heparin. Thus heparin anticoagulation prior to dissection and excision of a vein, may enhance early preservation of its endothelial cell function as evident by increased luminal release of prostacyclin.