Establishment Of A Rat Model Of Delayed Encephalopathy After Acute Carbon Monoxide Poisoning And Evaluation Of The Phenotype

Background There are about 480 million rural population is still using charcoal for heating in winter,acute carbon monoxide poisoning become the main disease in hospital emergency in China.The study found that the incidence of delayed encephalopathy after acute carbon monoxide poisoning(delayed encephalopathy after acute carbon monoxide poisoning,DEACMP)is 10% ~ 30% interiorly,and Abroad to 13~50% in the acute carbon monoxide poisoning patients.DEACMP is a kind of severe psychosis,that is not timely or improper treatment will cause serious sequelae,the disability rate is high,but its pathogenesis is unclear,resulting in the lack of clinical prevention and treatment method,One of the main reasons is the lack of an ideal rat model of DEACMP.Objective Using the method of abdominal compartment injection of high concentration CO gas to established the DEACMP rat model.Through clinical manifestations,behaviors of phenotypic,biochemical and pathological detection,brain electrical physiological detection evaluation the model consistent,established more consistent with the clinical characteristics of the DEACMP rat model,to provide a more reliable experimental animal modelsfor the pathogenesis and prevention of DEACMP.Methods(1)Rat single intraperitoneal injection CO with different doses(80ml/kg,100ml/kg,120ml/kg,150ml/kg)observed its different dose mortality and carbon oxygen hemoglobin(COHb)concentration changes in rat blood with 8h,to estimate the proper dosage and interval time to rats by intraperitoneal injection of CO gas,at the same time,detection of blood COHb content within the rat 16 h,trying to find out the suitable CO poisoning dose and the intervals time of intraperitoneal injection CO gas.(2)Using the Morris water maze evaluation method to detect poisoning after different periods in rats learning and memory ability of change.(3)Enzyme linked immunosorbent assay(Elisa)was used to detect the levels of MBP,NSE and S-100 B protein in serum of rats.(4)HE staining,LFB staining to detect the rats neuropathological changes: observed the rat neurons in the brain injury and brain white matter demyelination changes.(5)Cerebus multi-channel neural signal acquisition system acquisition EEG signal which comes from the experimental rat cerebral cortex and hippocampus,real-time observation of rat brain electrical changes,detection of different experimental group of brain electrical signal power spectral density,analysis the EEG changes of different time points in experimental rats.Results(1)The optimal dose was 100 ml/kg and the interval time was 4h for establish DEACMP rat model with interval intraperitoneal injection CO gas.(2)The day of rats by intraperitoneal injection of CO gas mainly as follows: shortness of breath,irritability,restlessness,walking instability,sleepiness,lethargy and other symptoms,the rat limbs and mouth skin exposed at cherry red,death rat postmortem findings in splanchnic hyperemia edema;number of rats after ACMP neurologic recovery,show again neuropsychiatric symptomsin the 2w,3w and 7w,mainly for muscle tension increased,walking instability,contraction of the arrector pili muscle,binge eating and so on DEACMP symptoms.(3)Mirrors water maze results show that,compared with the model group and the control group,The model group rats escape latency time increased,and the 2,3w model group is significantly different,with statistical significance(P < 0.05).Comparison within other model group,the2 w,3w model groups escape latency was prolonged,there was statistical significance(P<0.05),The running track chart of the positioning navigation experiment rats showed that the model rats were given a random swimming,and the control group was given the trend of swimming.(4)The MBP concentration in rats serum showed that: Compared with control group,the rats of model group was increased significantly(P<0.05),has the show of myelin damage,Comparison within the model group,the 2w,3w concentration of rats serum MBP increased significantly(P<0.05).The NSE concentration in rats serum increased significantly on 2w model group(P<0.05).The S-100 B protein concentration in rats serum increased significantly on1 w,2w and 3w model groups(P<0.05).(5)The results of HE staining showed that: after intraperitoneal injection of CO,the expression of neuronal degeneration and necrosis appeared in the hippocampus of rats with2 w,the most obvious manifestation of and 3w.Myelin staining after modeling 1w appeared demyelination,after modeled 2w was more obvious.The most obvious average optical density results show: the 1w,2w model group with those in the control group decreased significantly compared and build the average optical density of module and 7w,8w decreased significantly(P<0.05).(6)Rats by intraperitoneal injection of CO gas after one day,cerebral cortex EEG real-time monitoring appear the phenomenon that “abnormal-normal-abnormal”,Compared with30 s average power spectral density of rat hippocampal EEG signa:the model group of 1w,2w with all control group and 4w,7w,8w model group increased significantly(P< 0.05).Conclusions(1)By interval intraperitoneal injection CO gas to made DEACMP rats model,there have a considerable degree of compliance with clinical manifestations of DEACMP,in the behavioral phenotype,biochemistry,nerve pathology and brain electrophysiology and other levels.(2)The higher rate occurred DEACMP was 2 or 3 week after interval intraperitoneal injection CO gas to made DEACMP rats model.(3)By interval intraperitoneal injection CO gas to made DEACMP rats model:EEG detection appeared the phenomenon that “abnormal-normal-abnormal”of DEACMP rats,it is considered that EEG detection can be used as an effective index for evaluation of DEACMP rat model.