Ultrastructural analysis of human endothelial cells after hypothermic storage in organ preservation solutions

Background Protection of vascular endothelium is a critical factor in organ preservation for transplantation. This study aims at a morphological asses sment of endothelial cell injury in a comparison of storage solutions, usin g a cell culture model of cold preservation and rewarming. Material and methods. Human umbilical vein endothelial cells (HUVEC) were c ultured in monolayer and exposed to hypothermic storage in University of Wi sconsin (UW), histidine-tryptophane-ketoglutarate (HTK), and EuroCollins so lutions for 6 h and subsequent rewarming for 30 min or 6 h. Alterations of subcellular structures and cell-cell contacts were analyzed by transmission electron microscopy (TEM) and light microscopic assessment after actin and nuclear staining. Results. Structural alterations of mitochondria, endoplasmic reticulum, nuc lei, and cytoskeletal fibers as well as disruption of intercellular contact s were found after cold storage in HTK and EuroCollins solutions. In contra st, storage in UW solution resulted in minimum changes of stress fibers onl y. A rapid rearrangement of structural alterations was achieved during rewa rming in cell culture medium in all experimental groups. Conclusions. Preservation of endothelial cell structure is best achieved by UW solution. Ultrastructural cell damage is a direct consequence of hypoth ermic storage and is fully reversible during rewarming after Short storage times. (C) 1999 Academic Press.