P3‐021: The effect of estrogen on hyperphosphorylation of tau in hippocampus and cognitive function of ovariectimized rats

Alzheimer's disease (AD) is neurodegenerative disease associated with aging. It is a neurodegenerative disorder defined by progressive memory loss and cognitive impairment. In this research provide the evidence that estrogen may be a target for improve phposphorylation of tau and cognitive function in AD. We ovariectmized (OVX) SD rats to establish animal mode of low estrogen level. The level of hyperphosphorylation of tau at Ser199/Ser202 and Ser396/Ser404 sites in hippocampus and distribution were detected in the early stage after operation by Immunohistochemistry and Western blots. Meanwhile animal behavioral test was detected by water maze. We investigated estrogen replace treatment could reduce the level of hyperphosphorylation of tau at Ser199/Ser202 and Ser396/Ser404 sites in hippocampus and improve cognitive function of ovariectimized(OVX) rats in the early stage after operation. We found that the absence of estrogen may induce Alzheimer-like hyperphosphorylation of tau protein in the OVX rat's brain Moreover Short-time estrogen deficiency can weaken the capability of the OVX rats' cognition.