Abstract: Objective To investigate the changes of β-amyloid peptide(Aβ) in rats'blood and brain under the condition of chronic cerebral hypoperfusion. Methods Cerebral blood hypoperfusion rat model established by bilateral common carotid artery permanent ligation was used. Learning memory function were examined by Morris water maze. Radioimmunoassay and western blotting were employed to test the levels of Aβ and β-amyloid precursor protein(APP) in serum, cortex and hippocampal. Results The deficiency in learning-memory function began to appear from 1 m after hypoperfusion. Levels of Aβ in serum was significantly increased in each experimental group. Both APP and Aβ were increased from 3 m after hypoperfusion in hippocampal and the same changes occurred from 6m after hypoperfusion in cortex. Conclusion Chronic cerebral hypoperfusion can lead to increase of Aβ both in brain and blood which may play a very important role in early pathogenesis of Alzheimer's disease(AD).

Key words: chronic cerebral hypoperfusion, Alzheimer's disease, β-amyloid peptide, β-amyloid precursor protein