Research of the dynamic expression and effects of Nrf2 in delayed encephalophathy in rats after acute carbon monoxide poisoning

HE Lin; ZHANG Yi-wen; FAN Xing; ZHANG Yi-mei; LI Jing-lun

doi:10.3969/j.issn.1006-5725.2016.18.012

Abstract：Objective To study the effects of nuclear factor E2-related factor 2 (Nrf2) in delayed encephalopathy in rats after acute carbon monoxide poisoning. Methods One hundred and sixty-eight rats were randomly divided into three groups: forty-eight rats in the blank control group (BC group), sixty rats in the air control group (AC group) as well as in the carbon monoxide poisoning group (CO group). The DEACMP model was established by improved intraperitoneal injections. The animals were valuated at 1st ,3rd, 7th, 14th, 21th, 28th day after acute carbon monoxide poisoning. Tunnel method was used to test the pyramidal cell apoptosis in the hippocampal CA1 area. The expression of Nrf2 was tested by immunohistochemical method and Western Blot method. Result In the CO group, the apoptosis index (AI) started to increase from first day and achieved it's peak at the 7th day (20.20 ± 1.78), then began to decrease slowly. The apoptosis index was still higher than that in the other groups at 28th day. And the apoptosis index of the CO group was markedly higher than the other two groups at each time point. The Nrf2 protein started to increase from 1st day in the CO group , reached its peak at 3rd day (8.20 ± 1.08), reduced later, maintained at a high level at 28th day, and expressed significantly higher than other groups at each time point. Conclusions The Nrf2 has a linear correlation with apoptosis , and plays a dual role in DEACMP because it rapidly increased in first three days to against apoptosis. But it continuously has been excessive expressed from 7th to 28th day in promoting the apoptosis of hippocampus pyramidal cells and may be a positive factor in DEACMP.