Regulation of Glu Neuro-transmitter System and NR2B by Isoflovone in Ovariectomized Rats Brain

Objective: To explore the effects and mechanisms of isoflovone( IS) on spatial learning and memory and glutamate( Glu),N-methyl-D-asprtate receptor 2B( NR2B) in ovariectomized rats brain. Method:The young femal Sprague-Dawley rats were ovariectomized. Ovariectomized rats were randomly divided into five groups,model group,estradiol benzoate( EB) group,IS low dose group( IS1),IS middle dose group( IS2)and IS high dose group( IS3). EB group were treated with estradiol benzoate( 0. 2 mg·kg- 1,once each week)by intraperitoneal injection once a week. IS groups were treated with Isoflovone( 20,40,80 mg·kg- 1·d- 1) by gavage once daily. The spatial learning and memory performance of all rats were evaluated by Morris watermaze task. The change of Glu was measured by immunohistochemistry. The levels of NR2B protein was measured by Western blotting. Result: Compared with control group,the latency period of model group increased apparently( P 0. 05). Compared with model group,the latency period of control group and IS3 group decreased apparently( P 0. 05). Compared with control group,the magnitude of tinction of glutamic acid in hippocampus and the protein levels of NR2B in model group decreased apparently( P 0. 05). Compared with model group,the magnitude of tinction of glutamic acid in hippocampus and the protein levels of NR2B in EB group,IS3 group increased apparently( P 0. 05). Conclusion: Isoflovone can promote the ovariectomized rats' impairment of spatial learning and memory by changing the contents of Glu and increasing the protein levels of NR2B in hippocampus.