Arterial damage induced by cryopreservation is irreversible following organ culture

Objectives: the aim of the present study was to investigate the changes whi ch occur to the arterial wall following cryopreservation and thawing and to determine whether these changes are reversible after a week of culture in an organ bath. Materials and methods: I at iliac arterial segments were cryopreserved. Onc e thawed, the arterial segments were cultured for a period of 0, 1, 2, 4 or 7 days. Freshly isolated mt iliac vessels cultured for 7 days served as th e control group. Evaluation was made of ultrastructural changes, the expres sion of metalloproteinase activity (MMP-1, MMP-3 and MMP-9) and the apoptot ic stare of cells. Results: the freezing-thawing process induced damage to the arterial segmen ts compared to fresh control vessels. After 1 week of culture, arteries sho wed a high degree of tissue degeneration. Only a few individual endothelial cells remained on the luminal surface. There was a gradual increase in the proportion of apoptotic cells. The sequential expression of MMP-1 during t he first 2 days and subsequent expression of MMP-3 and MMP-9 were of most s ignificance. Conclusions: cryopreservation induced damage to the vessels which could not be reversed by organ culture. The changes observed in the expression of me talloproteinases may be indicative of the degenerative process which occurs in the extracellular matrix.