STIMULATED PROSTACYCLIN RELEASE BY CONDUITS USED FOR CORONARY-ARTERY BYPASS-GRAFTING

A direct comparison of the three coronary artery bypass conduits inter nal mammary artery (IMA), right gastroepiploic artery (RGEA), and saph enous vein (SV) concerning arachidonic acid (AA) stimulated release of the vasodilating and platelet inhibiting mediator prostacyclin was th e aim of the present study. Pieces of saphenous vein (n=16), right gas troepiploic artery (n=8), and internal mammary artery (n=19) were obta ined From patients undergoing coronary artery bypass grafting. After a resting phase of 30 min in HEPES medium arachidonic acid (AA) was add ed in order to stimulate prostacyclin release. Time-dependent producti on of the stable prostacyclin metabolite 6-ketoprostaglandin F1 alpha was determined following stimulation. Under basal conditions the IMA ( 12.4 ng/cm(2)) and RGEA (12.0 ng/cm(2)) released more prostacyclin tha n saphenous vein (4.0 ng/cm(2)). After AA stimulation 6-keto-prostagla ndin F1 alpha release at 30 min was as follows: IMA 806.0 ng/cm(2), RG EA 35.9 ng/cm(2), SV 82.3 ng/cm(2) (p<0.0001 within grafts, p<0.0001 b etween grafts, ANOVA for repeated measures). The internal mammary arte ry in comparison with the right gastroepiploic artery and saphenous ve in seems to be better protected against local thrombotic events and de velopment of coronary artery graft disease with the aid of the vasodil ating and platelet inhibiting mediator prostacyclin.