[Effect of focal hypothermia on traumatic brain edema and the content of lactic acid in the brain tissue in rats].

UNLABELLED

Objective To investigate the effect of focal hypothermia (LH) on traumatic brain edema and the content of lactic acid in rat brain tissue.

METHODS

One hundred and sixty-eight adult SD rats were randomly divided into 6 groups: Group A, sham injury group; Group B, traumatic brain injury controlled group; Group C, treated by LH with water at 0 degree C; Group D, treated by LH with water at 10 degrees C; Group E, treated by LH with water at 20 degrees C; Group F, treated by LH with water at 25 degrees C. All rats except those in Group A were subjected to traumatic brain injury (TBI) with Feeney's method. LH began for animals in Group C - F 30 minutes after the TBI. Regional brain temperature reached the target temperature of 31 degrees C within 20-30 minutes and maintained for 3 hours. Each group was divided into 4 sub-groups by investigating the duration after the TBI: 1, 3, 5 or 7 day sub-group. At the end of investigation, the rats were killed and water content (WC) and concentration of lactic acid (LA) in the brain tissues were measured.

RESULTS

Compared with Group A, WC and LA of Group B increased significantly at each investigation duration (P < 0.05). Compared with Group B, WC and LA of Group C did not change (P > 0.05), but those of Group D, E, and F decreased significantly (P < 0.05). WC and LA of group C were the highest among Group C - F.

CONCLUSION

Focal hypothermia with water of 10 degrees C, 20 degrees C, and 25 degrees C but not 0 degrees C has some effect on traumatic brain edema and the temperature at 20 degrees C and 25 degrees C are the better. The mechanism of focal hypothermia may be associated with inhibiting acidosis of lactic acid.