The Annals of Thoracic Surgery, Vol 45, 306-310, Copyright © 1988 by The Society of Thoracic Surgeons
Temperature dependency of calcium-induced reperfusion injury in the isolated rat heart
T Hamasaki, H Kuroda and T Mori
Second Department of Surgery, Tottori University School of Medicine, Yonago, Japan.
The temperature dependence of Ca-induced reperfusion injury was studied in
an isolated rat heart preparation. Hearts were subjected to 90 minutes of
hypothermic arrest (20 degrees C) followed by 15 minutes of reperfusion at
20, 28, or 37 degrees C with a reperfusate containing various
concentrations of Ca (0.1-2.55 mM). When reperfusion was started at 37
degrees C, the Ca concentration in the reperfusate significantly affected
both postischemic functional recovery and creatine kinase leakage.
Bell-shaped dose-response curves were observed. The optimal Ca
concentration for 37 degrees C reperfusion was between 0.3 and 0.7 mM. When
reperfusion was started at 20 degrees C, neither functional recovery nor
creatine kinase leakage was dependent on the Ca concentration in the
reperfusate. At 28 degrees C, functional recovery was not dependent on the
Ca concentration, however, creatine kinase leakage was. These results
indicate that Ca-induced reperfusion injury depends on the temperature of
the reperfusate and that the boundary temperature of the reperfusate at
which Ca-induced reperfusion injury becomes manifest seems to be near 28
degrees C.
