Abstract: Objective To observe the changes of neuron-specific enolase(NSE),S-100 protein and TBC in the blood of newborn rats at early stage of bilirubin encephalopathy,and the protective effect of mild-hypothermia on the brain.Methods 42 Wistar rats(7-day postnatal) were divided randomly into the group C(control group,n=10),group M0(normal-temperature group,n=17) and group M₁(mild-hypothermia group,n=15).The rats of the group C received physiological saline 0.5 ml,the rats in the groups of M₀ and M₁ were injected with bilirubin intraperitoneally(200 mg/kg) to establish the model of bilirubin encephalopathy.The changes of the content of NSE and S-100 protein in the blood of newborn rats,and the protective effect of mild-hypothermia on brain were observed.Results The animals with established bilirubin encephalopathy shown significant changes of neurobehaviour and pathological examination.Values of NSE and S-100 protein of the group M₁ decreased after the treatment of mild-hypothermia,and there was a significant difference compared with group M₀( P<0.01).Conclusion The mild-hypothermia has protective effect on brain of newborn rats with bilirubin intraperitoneally.

Key words: bilirubin encephalopathy, mild-hypothermia, neuron-specific enolase(NSE), S-100 protein, newborn rat