Viability of cryopreserved arterial wall: enzyme-histochemical and physiological markers

Use of cryopreserved small-caliber arterial allografts for arterial bypass procedures has been suggested. In addition to immunological tolerance, long term in vivo success of these grafts may be dependent on the viability of arterial cells after cryopreservation. Metabolic and functional capabilities of arterial smooth muscle cells were evaluated by studying the enzyme histochemical expressions of sheep carotid arteries after various time of cryopreservation (7 days, 90 to 150 days) and their contractile responses after freezing. The results indicated that cryopreserved arteries exhibited 4 features: (a) the enzyme activities were globally maintained, (b) the spontaneous endogenous oxido-reduction (NitroBT test) was reduced, (c) contractile responses against KCl and norepinephrine were abolished, (d) metabolic status of frozen arteries was independent of the duration of cryopreservation. These data suggest that cryopreserved arterial muscle cells may be depleted in electron donors and/or energy-rich nucleotides substrates. This defect is present after short or long time of cryopreservation.