EFFECTS OF DEPOLARIZING OR NONDEPOLARIZING PRESERVATION SOLUTIONS ON HUMAN ENDOTHELIAL-CELLS DURING COLD HYPOXIA

1. Hypothermic storage of whole organs flushed with a preservation sol ution is common practice in clinical transplantation. This procedure l eaves vascular endothelial cells in direct contact with the preservati on solution during the length of the cold ischaemic period. 2. Aiming to study the effects of organ preservation on vascular endothelium, we subjected cultures of human umbilical vein endothelial cells to hypox ic and hypothermic storage conditions in vitro for 3 or 16 h. Four pre servation solutions with different levels of sodium and potassium were tested. Morphometric analysis and Cr-51 leakage index were used to as sess monolayer continuity, cell viability and membrane integrity. 3. H ypothermic storage resulted in severe changes in endothelial cell morp hology with formation of intercellular gaps that destroyed monolayer c ontinuity after only 3 h. Cellular blebbing was a common feature in se riously damaged cells. 4. Morphometric analysis and Cr-51 leakage resu lts correlated well. No significant differences between the solutions tested were found after 3 h of hypothermic hypoxic storage. After 16 h , viability and monolayer continuity were significantly better preserv ed (Mann-Whitney, P<0.01) in cells stored in lactobionate-based soluti ons than in hypertonic citrate solutions. No significant differences w ere found between endothelial cells stored in extracellular versus int racellular types of solutions for the lactobionate-based solutions. 5. The results of the present experiment showed that after a period of h ypothermic hypoxic storage, vascular endothelial cells appeared morpho logically deformed and poorly attached in vitro. Lactobionate-based pr eservation solutions were more effective in preserving viability and c ontinuity. Protection of vascular endothelium under cold hypoxic condi tions could be a critical factor in successfully preserving organs for transplantation.