Effect Of Whole Body Deep Hypothermic Circulatory Arrest On Expression Of Smad2 And Smad4 In Cortex Neuron Of Rats

【Objective】To investigate the effect of deep hypothermic circulatory arrest (DHCA) on expression of Smad2 and Smad4 in cortex neuron of rats.【Methods】Thirty SD rats were divided randomly into three groups:deep hypothermic circulatory arrest (DHCA) group, normal temperature circulatory arrest (NTCA) group and normal animal control (NC) group. The animal model of closed-chest DHCA was established in rats by means of external cannulation. In DHCA group, circulatory arrest were performed in the deep hypothermia (20℃), the time was 10min; in NTCA group, circulatory arrest were performed in normal temperature, the time was 10min; in NC group without circulatory arrest and deep hypothermia.the time was 20min; and then cerebral cortexes were removed and then dissociated, use immunohistochemisty way to measure Smad2 and Smad4 Data were analyzed by software SPSS 13.0.【Results】The level of Smad4 expression of DHCA group and NTCA group was much higher than the NC group(P<0.05). The level of Smad4 expression of DHCA group was much higher than the NTCA group(P<0.05). The level of Smad2 expression of DHCA group and NTCA group was much higher than of NC group(P<0.05). The level of Smad2 expression of DHCA group was much higher than the NTCA group(P<0.05).【Conclusion】Ischemia can induce the expression of Smad2 and Smad4 while deep hypothermia could increase Smad2 and Smad4 expression. Deep hypothermia could have the protection effect to the brain while ischemia,and the increasing expression of Smad2 and Smad4 would be one of the mechanisms in protective effect of deep hypothermia.