| Objective:To establish a rat model of Obstructive sleep apnea syndrome(OSAS),to monitor the spatial learning and memory ability of OSAS rats.Tunel was used to detect apoptotic neurons in hippocampal,and the possible mechanism of cognitive impairment was explored by detecting the changes of NF-?B and Bcl-2 in hippocampus,which provided theoretical support for the prevention and treatment of diseases in the future.Methods:Twenty-four SD male rats were randomly divided into 4 groups,6 in each group.They were normal control group,and the model group was divided into 2w group,4w group and 6w group according to the length of feeding time after modeling.The rat model of OSAS was prepared by intraperitoneal injection of sodium hyaluronate gel,When the rats developed shortness of breath and abnormal breathing,the injection was stopped,which caused artificial airway obstruction to simulate OSAS.The successful determination of the model was to detect the oxygen saturation of the rat tail by multi-parameter nerve monitor before and after the injection of hyaluronic acid sodium gel in the rat model,and the difference between the two comparisons was statistically significant.The meaning can be judged successful.Rats fed 2w,4w and 6w rats and normal control rats were randomly divided into Morris water maze(MWM)to observe the spatial learning and memory ability of rats.After the water maze test,the rats were sacrificed and the hippocampus were taken for HE staining to observe the morphological changes;The apoptosis of hippocampal CA1 was observed by TUNEL staining;The expression of NF-?B in hippocampal neurons was observed by immunohistochemistry(IHC);The levels of NF-?B and NF-?B were detected by Western Blot analysis.Results:1.Compared with normal rats,it was found that the sensitivity of the sinus injection of sodium hyaluronate gel was decreased,the alertness was low,and the phenomenon of shortness of breath occurred.The multi-parameter nerve monitor was used to detect the blood oxygen of rat tail.The saturation indicates that the mean oxygen saturation before and after modeling is(95.1±2.3,87.2±2.1),and the lowest oxygen saturation is(87.6±2.1,75.6±2.5),respectively.The difference between the model and the model is statistically significant(P<0.05).2.Morris water maze test:(1)The escape latency of the two groups of experimental rats in the positioning navigation test was shortened with the increase of repeated training every day.The average latency of the normal control group was[(50.3±1.3 s on the first day,43.9±4.4 s on the second day,29.8±4.4 s on the third day,24.2±4.7 s on the fourth day,and 13.6±4.1 s on the fifth day)];The average latency of the 2w group[(52.4±2.5s on the first day,50.8±4.9s on the second day,41.8±4.0s on the third day,23.3±6.4s on the fourth day,and 18.0±2.8s on the fifth day)];Latency time[(58.1±6.0s on the first day,56.5±10.2s on the second day,45.0±7.0s on the third day,30.0±4.8s on the fourth day,25.2±8.6s on the fifth day)];The average latency of the 6w group[(The first day was 74.9±4.8 s,the second day was 69.6±7.6 s,the third day was 58.2±7.4 s,the fourth day was 50.0±8.6 s,and the fifth day was 43.9±15.0 s)].The average latency of the experimental rats was prolonged with the prolongation of feeding time,and the differences between the groups were statistically significant(P<0.05).(2)Space exploration test:the average number of times the control group crossed the original target platform was 4.7±1.8;the average number of 2w groups crossing the original target platform was 3.8±1.5;the average number of 4w groups crossing the original target platform was 4.0±1.4;6w The average number of times the group crossed the original target platform was 2.8±0.8.The results showed that the number of OSAS rats crossing the original target platform was lower than that of the normal group,and the difference was statistically significant(P<0.05).The water maze test showed that compared with the normal group,the average escape latency was significantly prolonged in the 2-week,4-week,and 6-week groups,and the number of crossing platforms was significantly reduced.3.HE staining showed that compared with the normal group,the hippocampal neurons of rats showed disorder,decreased cell number,increased cell gap,broken and condensed nucleus,and heavier with the prolongation of modeling time;The histochemistry showed that the expression of NF-?B increased in the experimental group and increased with the prolongation of modeling time.TUNEL staining showed that apoptosis of hippocampal CA1 region of OSAS rats aggravated with time,and The difference between normal rats was statistically significant(P<0.05).Western Blot results:The expression of NF-?B in the hippocampus of OSAS model was higher than that in the normal group(0.738±0.022 in the normal group,1.078±0.014 in the 2w group,0.965±0.031 in the 4w group,and 0.811±0.336 in the 6w group),while the expression of Bcl-2 was observed(1.048±0.013 in the normal group,0.525±0.020 in the 2w group,0.716±0.005 in the 4w group,and 0.914±0.031 in the 6w group).The expression of the two proteins was significantly different from the normal group,and the difference between the experimental groups was also statistically significant(P<0.05).Conclusion:1.Injection of sodium hyaluronate gel into the pharyngeal cavity of rats can result in an OSAS model;2.OSAS rats showed damage to spatial memory ability,which was aggravated with prolonged feeding time;3.The damage of cognitive function in OSAS rats may be related to the damage of hippocampal neurons;4.The mechanism of hippocampal neuronal apoptosis may be related to the increase of NF-?B expression and the decrease of apoptosis protein Bcl-2 expression in OSAS rats. |
PDF Full Text Request