Expression of iNOS and nNOS in acute carbon monoxide poisoning delayed encephalopathy and its correlation with neuronal degeneration and necrosis / 中华急诊医学杂志

ABSTRACT

Objective:To detect the expression of iNOS and nNOS in delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) and their correlation with hippocampal neuron degeneration and necrosis, and to explore iNOS and nNOS in DEACMP.Methods:Seventy-two adult male SD rats were selected and randomLy(random number) divided into the DEACMP group and normal group, with 36 rats in each group. The rats were given intraperitoneal injection of 99.99% CO gas without intervention. According to different time periods before and after dying and modeling, the two groups were divided into 6 subgroups pre-modeling, 1 d modeling, 7 d modeling, 14 d modeling, 21 d modeling, and 28 d modeling. In 6 subgroups during the modeling time, HE staining was performed to observe neuron degeneration and necrosis in hippocampal CA3 area, and immunohistochemistry and Western blot were performed to detect the protein expression of iNOS and nNOS in hippocampus. Statistical analysis was performed using SPSS 21.0 software. The measurement data were expressed as Mean±SD, and normality test and variance analysis were performed on the experimental results of each group. The mean comparison between each group adopted the Student’s t test of two independent samples. Correlation analysis was conducted between the relative expression of iNOS and nNOS protein and the degenerative necrotic neurons, Pearson correlation analysis was used for normal distribution, and Spearman rank correlation analysis was used for non-normal distribution. A P<0.05 was considered as statistically significant. Results:There was no significant difference in the counts of hippocampal neuron degeneration and necrosis between the two groups before modeling, on 1 d, and 7 d modeling ( P>0.05), while there were significant differences between the two groups on 14 d, 21 d, and 28 d modeling ( P<0.05). There was no statistically significant difference in the expression of nNOS protein between the two groups of rats before modeling, on 21 d, and 28 d modeling ( P>0.05), while there were statistical differences between the 1 d modeling, 7 d modeling, and 14 d modeling ( P<0.05). There was no statistically significant difference in the expression of iNOS protein between the two groups of rats before and 1 day after modeling ( P>0.05), while there were statistically significant differences between the 7 d modeling, 14 d modeling, 21 d modeling and 28 d modeling ( P<0.05). Correlation analysis between the expression of iNOS protein and the count of degenerated and necrotic neurons showed a positive correlation ( P<0.05). There was no correlation between the expression of nNOS protein and the count of degenerated and necrotic neuron ( P>0.05). Conclusions:iNOS plays an important role in the pathogenesis of DEACMP; nNOS is not consistently highly expressed in the hippocampus of DEACMP, and has no correlation with neuronal degeneration and necrosis in the CA3 region of the hippocampus.