The Study Of Expression Of Aβ_1-40 And ERα In The Different Brain Areas Of Ovariectomized Rats With Transection Of Fornix-hippocampal Fimbria And Estrogen Replacement Therapy

Objective To observe the expression of Aβ_1-40 and ERα in the brain of ovariectomized rats with transection of fornix-hippocampal fimbria and estrogen replacement therapy.Methods Experiment 1, Healthy female Wistar rats were randomly divided into 4 groups with ovaries and fornix-hippocampal fimbria as 2 factors and ovariectomized or not and transected or not as 2 levels: â‘ ovariectomized group;â‘¡fornix-hippocampal fimbria transected group;â‘¢fornix-hippocampal fimbria transected and ovariectomized group;â‘£control group. Experiment 2, Healthy female Wistar rats were randomly divided into 2 groups: â‘ estrogen replacement therapy group;â‘¡ovariectomized control group. There were seven rats in each group. Immunoreactive cells of Aβ_1-40 and ERα were stained by immunohistochemical way. The expression of Aβ_1-40 and ERα in the cortex, hippocampus CA₁, amygdale and Meynert nucleus were observed. Statistical analysis was performed with the analysis of variance (ANOVA) and screening method.Results The test of simple principal effect shows that without ovariectomized, fornix-hippocampal fimbria transected group exists effect on the expression of Aβ_1-40 in the cortex, hippocampus CA₁, amygdale and Meynert nucleus with significant increased immunoreactive cells (p<0.01) while without fornix-hippocampal fimbria transected, ovariectomized group exists effect on the expression of Aβ_1-40 in the cortex, hippocampus CA₁, amygdale and Meynert nucleus with significant increased immunoreactive cells (p<0.01) . The test of between-subjects effects shows that ovariectomized and fornix-hippocampal fimbria transected group exists reciprocating effect on the expression of Aβ_1-40 in the cortex , hippocampus CA₁, amygdale and Meynert nucleus (p<0.01) .The test of simple principal effect shows that without ovariectomized , fornix-hippocampal fimbria transected group exists effect on the expression of ERα in the cortex and Meynert nucleus with decreased immunoreactive cells (p<0.01) whilewithout fornix-hippocampal fimbria transected, ovariectomized group exists effect on the expression of ERa in the cortex, hippocampus CAi, amygdale and Meynert nucleus with significant decreased immunoreactive cells (p<0.01-0.05) . The test of between-subjects effects shows that ovariectomized groupand fornix-hippocampal fimbria transected group do not exist reciprocating effect on the expression of ERa (p>0.05) .Estrogen replacement therapy increased immunoreactive cells of ERa in several brain region (t=5.57⁹.09, pO.Ol) and improved plasma estrogen content (t=5.51, p<0.01) than the control group.Conclusion Increased immunoreactive cells of AP1.40 were expressed in the cortex, hippocampus CAi, amygdale and Meynert nucleus while immunoreactive cells of ERa were decreased in these areas. So we can say that the variation of Api.40 and ERa are correlated closely with pathological change of AD. Changes of vivo-strogen quantitative may affect the expression of ERa in several brain regions and estrogen treatment will result in increased immunoreactive cells of ERa.