EFFECTS OF PHYCOCYANIN ON EXPRESSION OF CytC mRNA AND CASPASE-3 mRNA AFTER FOCAL CEREBRAL ISCHEMIA/REPERFUSION IN RATS

摘要

Objective To study the effects of phycocyanin on the expression of Cytochrome C (CytC) genes and Caspase-3 genes after focal cerebral ischemia/ reperfusion in rats. Methods A rat middle cerebral artery occlusion (MCAO)/ reperfusion model was produced using the intraluminal filament method. The rats were divided into three groups ; sham operation group , model control group and phycocyanin group. After MCAO , the neu-robehavioral testing of all rats was made. The infarction area was evaluated with the method of 2 ,3 ,7-triphenyltet-razolium chloride ( TTC) staining. The expression of CytC mRNA and Caspase-3 mRNA were determined by in situ hybridization. Results In the sham operation group and the model control group , there was only a few CytC-positive cells were seen in the normal cerebral tissue. In the model control group , the upregulation of CytC mRNA began 6h after ischemia, reached a maximum at 12h (cortex) -24h (striatum) , then subsided gradually, but still in high level. In the phycocyanin group , CytC-positive cells were also mainly in cortex and striatum , but the number of the cells was significantly lower than the number of the model control group. The time-phase pattern of CytC mRNA in the phycocyanin group was similar to the pattern of the model control group. In the sham operation group and the model control group, there was only a few Caspase-3 -positive cells were seen in the normal cerebral tissue. In the model control group, the upregulation of Caspase-3 mRNA began 6h after ischemia, reached a maximum at 24h and subsided at 48 h, but still in high level. In the phycocyanin group, Caspase-3 -positive cells were also mainly in the penumbral area, but the number of the cells were significantly lower than the number of the model control group. The time-phase pattern of Caspase-3 mRNA in the phycocyanin group was similar to the pattern of the model control group. Conclusion The over-expression of CytC mRNA and Caspase-3 mRNA might play a key role in ischemic cerebral injury after MCAO. Phycocyanin could inhibit the over-expression of CytC mRNA and Caspase-3 mRNA in the cerebral cortex, and might play an important role in the protection of ischemic neurons.