THE ROLE OF PRESERVATION SOLUTIONS IN CORONARY ENDOTHELIAL DAMAGE DURING COLD-STORAGE

The effects of cold storage and type of preservation solution on coron ary endothelial function are not well understood. Experiments were des igned to evaluate coronary endothelial-dependent relaxation after a 4- hr cold (4-degrees-C) storage in different preservation solutions. Iso lated rat hearts were studied in the Langendorff aprparatus for corona ry endothelial function. After 30 min of stabilization, hearts were ar rested with a 10-min perfusion of 4-degrees-C crystalloid hyperkalemic cardioplegic solution (CHCS) containing 24 mmol/L of KCI and stored f or 4 hr in the following preservation solutions: CHCS, Krebs-Ringer's solution (KR), 0.9% NaCI (NS), and University of Wisconsin solution (U W). A fifth group was perfused and stored in UW solution. Endothelial- dependent and independent coronary artery vasorelaxation were tested, respectively, by infusing 5-hydroxytryptamine (5-HT) (1x10(-6) mol/L) and sodium nitroprusside (SNP) (1x10(-5) mol/L) before and 30 min afte r the storage period. In hearts stored in CHCS and KR, the coronary ar tery flow increase to 5-HT and SNP infusion were not significantly aff ected. However, in hearts preserved with NS and UW solutions, 5-HT cor onary response was significantly decreased, indicating endothelial dys function. In addition to these findings, coronary flow increase to SNP infusion was decreased in the group perfused and stored with UW, sugg esting smooth muscle damage. These experiments suggest that 4-hr cold storage in NS or UW impairs endothelial-dependent coronary relaxation in the isolated rat heart model.