[Expression of p38MAPK in the hippocampal CA1 region of rats with Abeta25-35-induced Alzheimer disease].

OBJECTIVE: To investigate the changes of p38MAPK expression in a rat model of Alzheimer disease (AD). METHODS: Seventy-two adult SD rats were randomized equally into 4 groups, and a single-dose injection of Abeta25-35 (dementia group), normal saline (saline group), SB203580 (inhibitor group), or DMSO (inhibitor control group) was administered into the lateral cerebral ventricle. Y-maze tast was performed to evaluate the behavioral changes of the rats after the injections, and on days 4, 7 and 14 after the injection, p38MAPK expression in the hippocampal CA1 area was measured by means of immunohistochemistry. RESULTS: On days 7 and 14 following Abeta25-35 injection, the training times, error number and total reaction time were significantly higher in dementia group than in saline group (P<0.05), but all these indices were significantly lowered in the inhibitor group as compared with the dementia group (P<0.05). Immunohistochemistry revealed obvious p38 expression in the dementia group 4 days after Abeta25-35 injection, which increased significantly with the passage of time (P<0.01). The gray scale in the inhibitor group was significantly higher than that in the dementia group (P<0.01). CONCLUSION: p38MAPK activation in the hippocampal CA1 area is an event that persists during the entire course of Abeta25-35-induced AD in rats, and the inhibitor SB203580 prevents p38MAPK expression and improves the learning and memory abilities of the rats.