The expressing changes of heat shock protein 70 in hippocampus of rat with Alzheimer's disease

Objective :To study the expressing changes of heat shock protein 70(HSP70)in hippocampus of rats with Alzheimer's disease(AD)induced by Aβ1-42 administrated into hippocampus.Methods :48 healthy SD rats were randomly divided into model group injected with Aβ1-42 and control group injected with normal saline into hippocampus.Y maze test was used to study the learning and memory ability of the rats at the 7th,14th and 21st day after injection into hippocampus.HSP70 expressions in hippocampus tissues were detected by RT-PCR and Western-blot technique.Results :The learning and memory ability of the rats in model group significantly decreased at the 14th and 21st day after injection than in control group(P0.05).Compared with control group,the HSP70 expressions in hippocampus tissues of the rats in model group were decreased gradually after injection Aβ1-42.These decreases were remarkablely significant at the 7th day(mRNA:0.34±0.05;protein:0.29±0.03)and 14th day(mRNA:0.32±0.06;protein:0.23±0.04)after injection(P0.05),especially at the 21st day(mRNA:0.29±0.04;protein:0.11±0.03)(P0.01).Conclusion :Aβ1-42 injection into rats hippocampus could result to the reduction of heat shock protein 70 expression in hippocampus tissues and this might play a role in the pathogenesis of AD.