Prolonged 24-hour subzero preservation of heterotopically transplanted rat hearts using antifreeze proteins derived from arctic fish.
BACKGROUND
Arctic fish survive subzero temperatures by producing a family of antifreeze proteins (AFPs) that noncolligatively lower the freezing temperature of their body fluids. We report 24-hour storage of mammalian hearts for transplantation at subzero temperatures using AFPs derived from arctic fish.


METHODS
Forty-two heterotopic transplantations were performed in isoimmune Sprague-Dawley rats. Harvested hearts were retrogradely infused with cold 4 degrees C University of Wisconsin (UW) solution and were preserved in a specialized cooling bath at two target temperatures, 4 degrees C and -1.3 degrees C for 12,18, and 24 hours (6 experiments/group). Preservation solutions were UW alone for the 4 degrees C group, and UW with 15 mg/mL AFP III for the -1.3 degrees C group. After hypothermic storage the hearts were heterotopically transplanted into isoimmune rats. Viability was assessed and graded on a scale of 0 to 6 (0 = no contractions to 6 = excellent contractions). Transplanted hearts were then fixed in vivo and were subject to electron microscopy and histopathologic examination.


RESULTS
None of the hearts preserved at -1.3 degrees C in UW/AFP III solution froze. All control hearts preserved at -1.3 degrees C without AFP protection froze and died at reperfusion. Viability of hearts preserved at -1.3 degrees C in UW/AFP III solution was significantly better after 18 hours of preservation, 30 and 60 minutes after reperfusion (median, 5 versus 3 and 6 versus 3, respectively; p < 0.05) and after 24 hours of preservation 30 and 60 minutes after reperfusion (median, 4.5 versus 1.5 and 5 versus 2, respectively; p < 0.05). Histologic and electron microscopy studies demonstrated better myocyte structure and mitochondrial integrity preservation with UW/AFP III solution.


CONCLUSIONS
Antifreeze proteins prevent freezing in subzero cryopreservation of mammalian hearts for transplantation. Subzero preservation prolongs ischemic times and improves posttransplant viability.
Amir
Gabriel
G
Heart Transplantation Unit, Department of Cardiac Surgery, Sheba Medical Center, Tel Hashomer, Israel. gabiamir@yahoo.com
Rubinsky
Boris
B
Horowitz
Liana
L
Miller
Liron
L
Leor
Jonathan
J
Kassif
Yigal
Y
Mishaly
David
D
Smolinsky
Aram K
AK
Lavee
Jacob
J
D000241:Adenosine / Q000627:therapeutic use; D000493:Allopurinol / Q000627:therapeutic use; D000818:Animals; D021343:Antifreeze Proteins, Type III / Q000627:therapeutic use*; D002314:Cardioplegic Solutions / Q000627:therapeutic use; D005978:Glutathione / Q000627:therapeutic use; D016027:Heart Transplantation; D007328:Insulin / Q000627:therapeutic use; D009926:Organ Preservation / Q000379:methods*; D019188:Organ Preservation Solutions; D011887:Raffinose / Q000627:therapeutic use; D051381:Rats; D017207:Rats, Sprague-Dawley; D016042:Transplantation, Heterotopic
D021343:Antifreeze Proteins, Type III; D002314:Cardioplegic Solutions; D007328:Insulin; D019188:Organ Preservation Solutions; C055206:University of Wisconsin-lactobionate solution; D000493:Allopurinol; D005978:Glutathione; D000241:Adenosine; D011887:Raffinose