PROTECTIVE EFFECTS OF VARIOUS PRESERVATION SOLUTIONS ON CULTURED ENDOTHELIAL-CELLS

Vascular endothelium represents the first target in organ preservation and plays an important role in reperfusion injury. Bovine aortic endothelial cells were cultivated and the most commonly used preservation solutions, such as University of Wisconsin, HTK (Brettschneider's histidine-tryptophane-ketoglutarate), and Euro-Collins solutions were tested on the endothelial monolayer. In addition, one group of cultivated cells was preserved with cold saline solution, and endothelial monolayers grown in culture medium were used as controls. The quality of preservation was assessed after 24, 48, and 72 hours of cold storage. Reperfusion was simulated and its effects were observed by reincubation in culture medium at 37 degrees C for 6 hours. The total number of cells, cell viability (determined using trypan blue exclusion), and morphologic alterations were determined. Prostacyclin release was evaluated as a biochemical marker. University of Wisconsin solution maintains more than 99% cell viability after rewarming after both 24 and 48 hours of cold storage. After 72 hours, 86.7% of cells were still viable. Preservation with HTK and Euro-Collins solution allowed cell survival for only 24 hours (96.7%, HTK; 49.9%, Euro-Collins), with no viable cells seen after 48 hours. The cold saline-preserved sample showed 57.8% viable cells after 24 hours and 29.7% after 48 hours. No viable cells were detectable after 72 hours. Light microscopy revealed several patterns of both structural damage and intracellular change (nucleus and cytoplasm) in the endothelial monolayer after preservation with HTK, Euro-Collins solution, and cold saline solution. No morphologic alterations were seen in the University of Wisconsin solution group for as long as 72 hours. Morphological damage and prostacyclin values were positively correlated. From these findings we conclude that endothelial cell culture is a suitable model for preservation studies and that University of Wisconsin solution seems superior to the other tested solutions at preserving vascular endothelium.