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.