Cryopreservation of innervation, endothelial and vascular smooth muscle function of a rabbit muscular and resistance artery

Cryopreservation of vascular tissues

Cryopreservation of human blood vessels may become an important tool in bypass surgery and peripheral vascular reconstruction. Ideally cryopreservation of a blood vessel should preserve functional characteristics comparable to those of fresh controls. The key advantage of cryopreservation is the fact that storage at deep subzero temperatures allows storage of structurally intact living vascular tissues for virtually infinite time. Originally developed for long-time storage of isolated cells, the techniques of cryopreservation of tissues are challenged by the fact that these are complex multicellular systems containing diverse types of cells with differing requirements for optimal preservation. Therefore, the post-thaw functional activity of vascular tissues is determined by the type of blood vessel and, in addition, by the cell packing effect. Moreover, evidence from pharmacological studies suggests that cryopreservation induces tissue specific changes in transmembrane signaling and the mechanisms coupling intracellular calcium release, sensitivity and calcium entry into the smooth muscle cells.

Maintenance of functional activity of human pulmonary arteries after cryopreservation

1. Human intrapulmonary arteries have been investigated in vitro in fresh tissue or after storage at -190 degrees C in foetal calf serum containing 1.8 M dimethyl sulphoxide. 2. After cryopreservation of the arteries, maximal contractile force was reduced to 76%. This was assessed by the responses (in g) to 10 nM of the thromboxane analogue, U 46619. 3. Constricting agonists such as noradrenaline, 5-hydroxytryptamine, histamine and U 46619 stimulated fresh and frozen/thawed arteries producing pD2 values similar to the respective values determined on fresh tissues. 4. Endothelium-independent relaxant responses of U 46619-precontracted arteries to prostacyclin (PGI2), aminophylline and papaverine were generally unchanged after storage. The same was true for relaxant response to the potassium channel activator P-1075 whereas the pD2 values for SDZ PCO 400, RP 49356 and cromakalim were somewhat diminished. 5. Nevertheless, a significant correlation was obtained when the apparent pD2 values for all agonists on fresh and frozen/thawed tissues were compared (P less than 0.001). 6. The evidence suggests that after cryopreservation of human intrapulmonary arteries at -190 degrees C, mechanisms of both contraction and relaxation are well-maintained.