RESUMEN
Objective To explore the effects of lithium on expressions of cyclin-dependent kinase 5 (CDK5) and protein phosphatase 2A (PP2A) in the brains of chronic aluminum exposure rats so as to further understand the mechanism of lithium's inhibition on tau phosphorylation. Methods We divided 12 chronic aluminum chloride exposure rats into treatment group and non-treatment group (6 rats in each). Treatment group was given lithium chloride (200 mg/kg?d) via gastric perfusion daily for 6 weeks,while the non-treatment group sodium chloride at the same dosage and the normal group (6 non-aluminum exposure rats of the same month old) without intervention. Six weeks later,all the rats received Morris water maze test for learning memory function; CDK5 and PP2A expressions and phosphorylated tau protein level in rat hippocampus were determined by Western blotting. Results Compared with normal group,non-treatment of chronic aluminum exposure group showed higher phosphorylated tau protein level and CDK5 expression in the brain (P0.05). Conclusion Lithium may reduce tau phosphorylation and neurofibrillary tangle formation by inhibiting the expression of CDK5.