Altered endothelial and smooth muscle cell reactivity caused by University of Wisconsin preservation solution in human saphenous vein

Purpose: We have investigated the effect of University of Wisconsin (UW) solution at different temperatures on endothelial and smooth muscle cell function of the human saphenous vein to define the efficacy of UW solution as a preservation solution for saphenous vein conduits. Methods: Saphenous vein segments from 38 patients undergoing coronary artery bypass a surgery were examined with an isolated organ bath technique to monitor changes in vessel reactivity. Results: Endothelial-dependent relaxations to acetylcholine were attenuated after incubation in UW solution at both 4 degrees C and 28 degrees C (p < 0.05, n = 10). In contrast, relaxations to sodium nitroprusside were unchanged after incubation in UW solution at both temperatures (n = 8). The responses to 90 mmol/L KCl were increased at both 4 degrees C and 28 degrees C, respectively. Tyrode's: 27.2% +/- 3.1% and 23.8% +/- 3.0%, UW: 64.7% +/- 8.0% and 73.1% +/- 11% (p < 0.001). In addition, the responses to 5-HT were enhanced at 4 degrees C and 28 degrees C (p < 0.05). In contrast, responses to noradrenaline were enhanced only at 28 degrees C compared with the responses after incubations in Tyrode's solution (p < 0.05, n = 6). Furthermore U46619 (0.3 nmol/L to 1 nmol/L) responses were augmented at 4 degrees C (p < 0.05, n = 7). The potency (pD(2)) values for each agonist were not significantly different after incubations in UW solution. Conclusions: We conclude that UW solution produces attenuation of acetylcholine relaxations and temperature-dependent increased reactivity of smooth-muscle cell function in the isolated human saphenous vein. These studies document the complex interactions brought about by UW solution on the different components of the vascular wall that need to be elucidated further if this solution is to attain a place in vascular preservation.