Endothelial and smooth muscle changes of the thoracic and abdominal aorta with various types of cryopreservation.
BACKGROUND
There is a need for cryopreserved arterial allografts in vascular surgery. Vitrification was examined as an alternative to slow cooling. Function of endothelial and adjacent cells was evaluated in the thoracic and abdominal regions of the porcine aorta.


METHODS
Aortas from young pigs were harvested and cryopreserved with several treatments: slow cooling at 1 degrees C/min with 10% dimethyl sulfoxide (DMSO) and vitrification with a vitrification solution (VS), performed either in the presence (medium) or in the absence (air) of the cryoprotective medium surrounding the sample. Tetrazolium salt reduction and oxygen consumption were used to assess the mitochondrial activity of the endothelial cells and smooth muscle cells from the aorta.


RESULTS
Fresh aorta showed an increased function from below the aortic arch to the iliac branch. Exposure to cryoprotective solutions reduced significantly the oxygen consumption of the abdominal sections. Samples from the thoracic region had a better response to cryopreservation than those from the abdominal region. There was a significant reduction in tetrazolium salt reduction and oxygen consumption when the samples were cryopreserved immersed in the medium. Significant flaking of the endothelium was observed after vitrification and contributes generally to lower the function.


CONCLUSIONS
The thoracic region of the aortic wall was more tolerant to the preservation injury, and freezing with DMSO in air offered a better choice of preservation.
Arnaud
F
F
Transfusion and Cryopreservation Research Program, NMRC, Bethesda, Maryland 20889-5607, USA. arnaudF@nmripo.nmri.nnmc.navy.mil
D000818:Animals; D001012:Aorta, Abdominal / Q000378:metabolism / Q000648:ultrastructure*; D001013:Aorta, Thoracic / Q000378:metabolism / Q000648:ultrastructure*; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000378:metabolism / Q000648:ultrastructure*; D007101:Immersion; D066298:In Vitro Techniques; D008855:Microscopy, Electron, Scanning; D009131:Muscle, Smooth, Vascular / Q000378:metabolism / Q000648:ultrastructure*; D010084:Oxidation-Reduction / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects; D013552:Swine; D013778:Tetrazolium Salts / Q000378:metabolism; D013844:Thiazoles / Q000378:metabolism; D014022:Tissue Survival / Q000187:drug effects
D003451:Cryoprotective Agents; D013778:Tetrazolium Salts; D013844:Thiazoles; C022616:thiazolyl blue; D004121:Dimethyl Sulfoxide