Effects of storage solutions on contraction and relaxation of isolated saphenous veins

Saphenous veins are placed frequently in storage solutions before use as coronary bypass grafts. Controversy remains regarding which solution is optimal for the preservation of endothelium and vascular smooth muscle viability. Thus, this study measured the effect of four different storage solutions on saphenous vein smooth muscle and endothelial cell function. Saphenous vein segments from five baboons were stored for 3 h in one of four storage solutions consisting of physiological salt solution (PSS), University of Wisconsin solution (UWS), normal saline solution (NSS), or autologous whole blood (WB). Following storage, veins were suspended for isometric tension recording in tissue baths filled with PSS. Veins stored in PSS, UWS, and NSS showed similar contractile amplitude and agonist sensitivity to norepinephrine (10(-8) -10(-4) M) and KCl (20-100 mM). However, veins stored in WB contracted 31% less to KCl on average than those stored in the other three solutions (p < 0.05). The direct vascular muscle vasodilator, papaverine (10(-7) -10(-4) M), and the endothelium-dependent dilator, A23187 (10(-5) M), relaxed all vein preparations equally well. These results suggest that after storage in PSS, UWS, and NSS, contractile and relaxant vascular responses are similar in isolated saphenous veins. However, although veins stored in WB show comparable relaxation responses, they demonstrate an impaired vascular contraction immediately after storage. We conclude that storage of veins in blood may immediately modify vascular smooth muscle function.