| Objectives To explore the protective effects of umbilical cord tissue transplantation and its underlying mechanism on radiation-induced learning and memory impairment in rats.Methods One hundred and twenty SD rats were randomly divided into three groups:control group,model group and treatment group.Model group rats were given whole brain X-ray irradiation dose of 20 Gy.In the treatment group,the rats were given a whole brain X-ray radiation dose of 20 Gy,and the umbilical cord tissue transplantation was performed immediately on the back of the rats.Control rats were not given any special treatment.The weight changes of rats in each group were observed at week 1,week 2,week 4 and week 8after irradiation.Hidden platform experiment and space exploration experiment were conducted on each group of rats at each time point,and the differences between groups were observed.The number and morphology of neurons in hippocampal area were observed by HE staining after sampling at different time points.The microglias and astrocytes were observed by immunohistochemical staining.The expression of IL-6 and other associated signaling proteins of NF-?B pathway in the hippocampus were observed by western blotting.Results 1 During the 1?2 week after radiotherapy,the body weight of the control group increased with time,and that of the model group and the intervention group decreased.and the body weight of the model group and the intervention group decreased to the lowest value on the 7th and 8th days,respectively,with loss of appetite,coarse hair,yellowing and obvious head and neck,mandible and part of neck hair loss,and vomiting.He then slowly gained weight around day 12.At 1,2 and 4 week the weight of the control group was higher than that of the model group and the treatment group with statistically significant difference(P<0.05).There was no significant difference in the weight of the rats in the 8th week;2 At week 2,4 and 8,the incubation period of the rat model group was higher than that of the control group with statistically significant difference(P<0.05).At week 4,the incubation period of rats in the treatment group was higher than that in the control group with statistically significant difference(P<0.05).The incubation period of rats in the treatment group was lower than that in the model group with statistically significant difference(P<0.05).Most of the model groups are dominated by marginal search strategy.Marginal and trend search strategies were used in the treatment group;3The number of rats crossing the platform at week 2 and 4 was higher in the control group than in the model group with statistically significant difference(P<0.05).In the quadrant time of the platform,the rats in the three groups were all higher at week 4 and 8 than at week 2 with statistically significant difference(P<0.05);4 According to HE staining in the hippocampal area of rats in each group,neurons in the control group were arranged neatly,with clear cytoplasm,round or oval nuclei,uniform chromatin distribution and clear nucleoli.In the model group,the arrangement of some neurons was disordered,the contraction of the cell body was triangular or irregular,and the structure was unclear.The number of neuron degeneration,necrosis and loss in the treatment group was less than that in the model group;5 By observing the expression of neurons,microglia cells and astroglia cells in the hippocampal area model group of rats with immunohistochemical staining,the expression of neurons in the model group was less than that in the control group with statistically significant difference(P<0.05).The expression of activated microglia in the cell model group and the treatment group was higher than that in the control group with statistically significant difference(P<0.05).The number of activated microglia decreasedwith time.The expression of astrocytes in the model group was higher than that in the control group with statistically significant difference(P<0.05).The expression of astrocytes increased with time;6 The expressions of TLR4,P65 and IL-6 in the model group and the treatment group were all higher than those in the control group at week 1,and the differences were statistically significant(P<0.05).The expressions of IL-6 in the model group were higher than those in the treatment group with statistically significant difference(P<0.05).At week 2,TLR4,NF-?B P65,IL-6 and Bcl-2 /Bax were significantly higher in the model group and the treatment group than in the control group with statistically significant difference(P<0.05).At week 4 and 8,the expression of IL-6in the model group and treatment group was higher than that in the control group with statistically significant difference(P<0.05).Conclusions 1 Whole brain irradiation can cause behavioral?pathological changes as well as learning and memory impairment in rats;2 Umbilical cord tissue may alleviate learning and memory impairment induced by whole brain irradiation in rats.Figure18;Table4;Reference 173... |
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