effect of combination therapy using hypothermia and granulocyte colony-stimulating factor in a rat transient middle cerebral artery occlusion model

background: stroke is the third leading cause of death. hypothermia has been recognized as an effective method in reducing brain injury. in this study, we assessed the effects of granulocyte colony-stimulating factor (g-csf) as a neuroprotective agent and mild hypothermia on mortality, behavioral function, infarct volume, and brain edema in wistar rats. methods: forty male rats were used in five groups (eight rats in each group): control, hypothermy, g-csf, combination hypothermy + csf, and sham. rats were anesthetized by injection of chloral hydrate (400 mg/kg) intraperitoneally. transient cerebral ischemia was induced by 60-min intraluminal occlusion of left middle cerebral artery. hypothermia, initiated at the time of reperfu sion and g-csf was started one hour after reperfusion at a dose of 15 mg/kg subcutaneously. the motor behavior was measured using garcia’s index and animals were assigned for the assessments of infarction, brain swelling, and mortality rate. results: the mortality was 38.46% (control group) and reduced in other groups. neurological deficit score of control group (40.31 ± 1.56) was significantly lower than in treatment groups. the total cerebral infarct volume of treatment group was significantly lower than control group (43.96 ± 44.05 mm3). treatment with hypothermy plus g-csf (2.69 ± 0.24%) could significantly reduce brain swelling volume than other treatment groups. conclusion: our major finding is that mild hypothermic treatment plus g-csf significantly reduced mortality rate and edema and improved neurological function. the results suggest that the combination of hypothermia and g-csf is more effectively than other treatment groups being used alone.