Mild hypothermia improves ischemic brain function via attenuating neuronal apoptosis.

In addition to pharmacological treatment of ischemic stroke, hypothermia has been proposed to be a therapeutic option for protecting brain cells from ischemic death. Less is known about the molecular mechanisms underlying this hypothermic protection of ischemic cells, which we have investigated in rats. In four groups of experiments, ischemia under the conditions of normothermia and mild hypothermia as well as sham-operation under these two conditions, we have analyzed quantitatively the score of neurological impairment and the expression of second mitochondrion -derived activator of caspases (SMAC), an index of cellular apoptosis. Compared with ischemia under normothermia, the treatment of mild hypothermia significantly improves brain function and lowers SMAC expression. Our results indicate that the mild hypothermia protects the functions of brain cells from ischemic impairment through attenuating apoptotic death.