Tyrosine Oxidation Products Induce Spatial Learning and Memory Impairments in Rats

Abstract:

To explore the effects of tyrosine oxidation products（TOP） on the spatial learning and memory of rats and hippocampus. 40 SD rats are divided into four groups：Control（normal diet），Tyr group（add 0.44%Tyr），TOP1group（add 0.22% tyrosine oxidation products） and TOP2 group（add 0.44% tyrosine oxidation products）. After 24-week feeding，Morris water maze is used to test the spatial learning and memory of rats. Protein and lipid oxidation products in hippocampus are measured. Expressions of antioxidation- and inflammation- related genes are detected using RT-PCR. The results show that，after 24-week feeding，compared with Control and Tyr group mice，TOP1 and TOP2 group rats showed impaired spatial learning and memory in Morris water maze；hippocampal MDA，4-HNE，Dityr，3-NT and Aβ40 are significantly increased（p<0.05）；expressions of Nrf2、NF-κB and iNOS were significantly up-regulated（p<0.05）. Thus，tyrosine oxidation products induce oxidative damage to rats hippocampus，accumulation of lipid and protein oxidation products in hippocampus，and impair the spatial learning and memory of rats.