Expression of cold-inducible RNA-binding protein mRNA in the rat's brain under hypothermia

Objective To observe the expression of cold-inducible RNA-binding protein (CIRP)mRNA in different brain regions in rats under different hypothermic conditions.Methods Mild hypothermic models were established in rats through the combined application of anesthesia and body surface cooling with alcohol.Rats were divided into 5 groups:control,30 min hypothermia,1h hypothermia,2h hypothermia and 4h hypothermia(n=5 in each group).The body temperature of rats was kept stable and rats were executed at corresponding time points.Then they were decapitated and their hypothalamic,hippocampal and cortical brain tissues were removed.The expression of C1RP mRNA in different brain regions was measured at different time points of hypothermia by semi-quantitative reverse transcription-polymerase chain reaction(RT-PCR).Results The expression of CIRP mRNA was the strongest in hippocampus and the lowest in hypothalamus under normothermia.After 1h hypothermia, the expression of CIRP mRNA in hypothalamus was firstly increased;after 2h hypothermia,its expression in hippocampus and cortex began to increase but the expression remained unchanged in hypothalamus.After 4h hypothermia,its expression in hippoeampus was higher than that at 2h,but the expressions still maintained their previous levels in hypothalamus and cortex.Conclusion Expressions of CIRP mRNA have all been increased significantly in different brain regions of rats under hypothermic conditions and the expression varies among different brain regions,indicating that the high expression ofCIRP mRNA might participate in the hypothermic protection of the brain against injury.