HIF-1α And EPO Expression In Rat Brain’s Hippocampus Of The Delayed Effects Of Encephalopathy After Acute Carbon Monoxide Poisoning

Abstract:Ojective:By means of establishing the acute carbon monoxide poisoning(DEACMP)rat models,to observe the expression of HIF-1α and EPO in the corresponding table of changes in animal models, to determine the use in the pathogenesis of DEACMP.Methods:78healthy adult male SD rats (SPF),which’s weight between240-280g,were randomly divided into three groups:18in control group (BC group),30in air control group (AC group),30in delayed encephalopathy after acute carbon monoxide poisoning group (CO group).The CO group was established by intraperitoneal injection of delayed encephalopathy rat model of acute carbon monoxide poisoning, AC group were treated with intraperitoneal injection of injected air,while BC group weren’t be treated.After the poisoning within ld,3d,7d,14d,21d,28d,the three group were divided into six subgroup.Both CO and AC group had5rats in their subgroups,and BC group had3rats in subgroup.Use Morris water maze test memory to test and observe the orientation and cognitive function of the rats,which were got acute CO poisoned.Each rat’s brain tissue sections were used HE to observe the pathologic changes in hippocampus of rats staining, immunohistochemical staining to detect the hippocampus HIF-1α, immunohistochemical staining to detect the hip- pocampus HIF-la, EPO protein, detected the apoptosis of pyramidal cells in hippocampus by Tunel apoptosis detection method. Results:1.The result of Morris water maze test memory:The CO group had the average extended the incubation period after toxiced.And after toxiced14d,21d and28d,CO group had more statistically significant than BC and AC group(P<0.01). CO group of rats after infected in the first Ⅳ quadrant exercise got shorten the time trend,and after toxiced14d and28d,CO group had more statistically significant than BC and AC group(P<0.05). The CO group’s rats had a tendency to reduce after being toxiced.When28d after infection,CO group had a lower tendency than the other groups,and the difference had statistically significant(P<0.05).2.HE:CO group’s rats had reduced the hippocampus pyramidal cell number,the cell arrangement were loosen,the cells were edema,etc.3.TUNEL testthe hippocampus pyramidal cell in CO group increased the apoptosis after being3d’s toxiced,and increased to the peak in7d.There were still minor cell apoptosis in the28d.Every apoptotic indexhad more statistically significant(P<0.01) than BC and AC group.4.Immunohistochemical staining results:1) the expression of HIF-1α:HIF-1α in BC group and AC group was significantly higher than expression in CO group.The expression in the CO group increased after Id after the exposure, in the3d reached the peak, then decreased gradually, and28d still had a higher expression.There were significant differences (P<0.01) than in BC and AC group.2)The expression of EPO:EPO in BC group and AC group expressed less than in CO group.There was statistically significant difference (P<0.05) in CO group than in BC and AC group. EPO expression increased rapidly from exposure after Id, reached the peak after3d,gradually reduced in the7d.The CO group had significant difference between BC and AC group(P<0.01).Conclusions:1.It was a easier way to study the DEACMP by the intraperitoneal injection of CO.2.Morris water maze experiment is a more reliable basis to make a preliminary judgment in DEACMP rats.3.The expression of HIF-1α might participate in the paroxysm of DEACMP by inducing the acute CO poisoning to late apoptosis of hippocampus neurons.4.One of the causes in the paroxysm of DEACMP might be the weaken neuroprotective effect after the acute CO poisoning.