Effect of moderate hypothermia on lipid peroxidation in canine brain tissue after cardiac arrest and resuscitation.
OBJECTIVE
We sought to examine the effect of moderate hypothermia (30 degrees C to 32 degrees C) initiated after resuscitation on the scavenging systems of free radicals and lipid peroxidation in canine brain tissue after cardiac arrest and resuscitation.


METHODS
Twenty-one dogs were divided into four groups: group A, nonischemic controls (shams) (n = 4); group B, 15-minute cardiac arrest without reperfusion (n = 4); group C, 15-minute cardiac arrest and standard resuscitation (n = 6); and group D, 15-minute cardiac arrest and hypothermic resuscitation (n = 7). During the period of 10 to 120 minutes after resuscitation, brain temperature and core temperature in group D remained at 30 degrees C to 32 degrees C and were 4 degrees C to 5 degrees C lower than in group C. For each dog, a sample of right parietal cerebral cortex was obtained from group A, group B, or from group C and group D at 2 hours after resuscitation. The sample was assayed for tissue malondialdehyde (MDA), the content of reduced glutathione (GSH), and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-PX).


RESULTS
In group B, a 15-minute cardiac arrest induced an increase in MDA, a significant reduction of GSH, and no change in SOD and GSH-PX activities compared with group A. In group C, there were further increases in MDA and reductions in GSH content and GSH-PX activity compared with group A; SOD activity remained substantially unchanged. The content of MDA was higher in group D than in group A but less elevated in group D than in group C. The GSH content and SOD and GSH-PX activities were significantly higher in group D than in group C.


CONCLUSIONS
Moderate hypothermia initiated after resuscitation can significantly inhibit the accumulation of lipid peroxidation products and the consumption of free radical scavengers in the brain tissue.
Lei
B
B
Department of Anesthesiology, First Affiliated Hospital, Hunan Medical University, Changsha, People's Republic of China.
Tan
X
X
Cai
H
H
Xu
Q
Q
Guo
Q
Q
D000818:Animals; D001831:Body Temperature; D001921:Brain / Q000378:metabolism*; D004285:Dogs; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D006323:Heart Arrest / Q000378:metabolism* / Q000503:physiopathology / Q000628:therapy*; D007036:Hypothermia, Induced; D008054:Lipid Peroxides / Q000378:metabolism*; D008315:Malondialdehyde / Q000378:metabolism; D012016:Reference Values; D012151:Resuscitation; D013482:Superoxide Dismutase / Q000378:metabolism
D008054:Lipid Peroxides; D008315:Malondialdehyde; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005978:Glutathione