ARTERIAL SMOOTH-MUSCLE FUNCTION AFTER PROLONGED EXPOSURE TO A MEDIUM CONTAINING DIMETHYL-SULFOXIDE (ME(2)SO) AND STORAGE AT -196-DEGREES-C

Changes in smooth muscle responsiveness were investigated in vitro aft er storage of canine femoral arteries at room temperature (21 degrees C) and in liquid nitrogen (-196 degrees C) in Krebs-Henseleit solution containing 50% fetal calf serum, 2.0 M dimethyl sulfoxide, and 0.1 M sucrose as cryoprotectants. Both contractile responses to noradrenalin e and relaxant effects of bimakalim were unchanged after exposure of a rterial smooth muscle preparations for 1 h to the cryomedium without f reezing. However, after exposure of the tissues for increasing time pe riods to the cryomedium with subsequent cryopreservation the post-thaw functional recovery was progressively diminished. Optimal post-thaw f unctional recovery was obtained with tissues that had been frozen with in 10 min of being placed in the cryomedium. The results suggest that exposure to the cryomedium without freezing is well tolerated by the a rterial smooth muscle, whereas a progressive reduction of the contract ile activity occurs with prolonged exposure of the preparations to roo m temperature cryomedium before starting the cooling process. (C) 1994 Academic Press, Inc.