Effects Of Aerobic Exercise On Learning And Memory, Aβ-related Gene Expression And Lipid Peroxidative Of AD Rats

Alzheimer's disease (AD) is a heterogeneous, neurodegenerative disease with multiple pathogenesis, the current accepted theories include:the (β-amyloid toxicity theory, free radical damage theory, gene damage theory, abnormal phosphorylation of tau, cholinergic damage theory, excitatory amino acid toxicity theory and so on. Among these theories, theΔβtoxicity theory is the dominant theory. There are many evidences that Aβis the common pathway of various pathogenesis, and the key factor in the occurrence and development of AD. ROS can promote the formation of Aβand inhibition of Aβdegradation; at the same time, Aβis also involved in the process of free radical oxidative damage. The pathogenesis of AD is very complicated, so clinical treatment just alleviate the symptoms, can not be cured in clinical currently. In addition, studies found that sports can regulate the produce and clearance of Aβ, reduce the excessive phosphorylation of tau, repair and activate the brain cholinergic sysiem, increase the antioxidant enzyme activity, reduce the generation of lipid peroxides, and promote neurogenesis, to prevent and treat Alzheimer disease from multiple perspectives.Objective:This research focus on the effects of aerobic exercise on learning and memory, Aβ-related gene expression and lipid peroxidative of D-galactose-induced AD rats, investigating the physiological and biochemical mechanisms of aerobic exercise on prevention and treatment of Alzheimer's disease.Methods:30 male Spargue-Dawley rats are divide into Control Group(C, n=10), Injected Group(D, n=10) and Excerse Group(S, n=10). Group D and S of rats were injected by D-galactose(120mg/kg-d) while the Group S of rats had aerobic treadmill training from Monday to Friday for 8 weeks.30 rats all participated in the test of Morris water maze at the 9th week. Then, test the SOD activity and MDA content using test kit; inspecting the expression of APPmRNA, ADAM17mRNA, BACE-1mRNA and PS1mRNA by RT-PCR.Results:(1) According to the date in the Morris water maze test, C group performed the best, followed by the S group, D group was the worst.(2) The SOD activity in hippocampal of D group rats was lower than C group, the MDA content was higher than C group with significant differences; S group rats' SOD activity in hippocampal was significantly higer than D group, the MDA content was lower than Group D.(3)The expression of ADAM 17 in hippocampal of D group was significantly lower than C and S group; the expression of APP, BACE-1 and PS1 was higher than C and S group.Conclusions:(1) 8-week D-galactose injection could decrease the function of spatial learning and memory in rats while 8-week aerobic treadmill training would improve the spatial learning and memory function.(2) 8-week D-galactose injection could decrease the activity of SOD and increase the content of MDA while 8-week aerobic treadmill training would increase the activity of SOD, decrease the content of MDA.(3) 8-week D-galactose injection could down regulate the expression of APPmRNA, BACE-1mRNA and PS1mRNA, up regulate ADAM17mRNA, while 8-week aerobic treadmill training would up regulate the expression of ADAM 17mRNA, down regulate the APPmRNA, BACE-1 mRNA and PS 1 mRNA.