卵巢切除及雌激素替代对大鼠脑单胺氧化酶和行为学的影响

Effects of ovariectomy and 17β-estradiol replacement on brain monoamine oxidase activity and its praxiology in rats

目的观察卵巢切除对大鼠脑内单胺氧化酶和学习记忆的改变及雌二醇对其影响的可能机制。方法采用Morris水迷宫方法观察切除卵巢后大鼠的行为学改变 ,用比色法测定了大鼠大脑皮层和海马中单胺氧化酶 (MAO)活性。结果大鼠切除卵巢后 6周 ,Morris水迷宫试验逃避潜伏期 ( 88.9± 3 5 .1)明显延长 ,记忆频度 ( 18.7± 2 .7)减退 ,大鼠大脑海马组织中单胺氧化酶 (MAO)活性升高 ( 2 2 3 .0± 66.8) ,与Sham组比较 ,P均 <0 .0 5。应用雌激素可以改善记忆障碍 ,并能拮抗因卵巢切除造成大鼠大脑海马组织中MAO活性的升高 ( 13 4.2± 46.6,P <0 .0 1) ,大脑皮层MAO活性无变化。结论大鼠卵巢切除可以造成学习记忆减退 ,雌激素替代能改善学习记忆 ,同时雌激素能抑制海马组织中MAO活性 ,这可能是改善大脑功能的机制之一。

ObjectiveTo investigate the influence of ovariectomy and 17β-estradiol (E 2 ) treatment on the brain monoamine oxidase (MAO) activity and learning and memory in rats and its mechanism of action. MethodsTwenty-four the adult Sprague-Dawley female rats were randomly dividing into three groups Sham–ovariectomized (Sham)、ovariectomized (OVX) and 17β-estradiol (E 2 ) . Using Morris water maze ,the change of learning and memory function and the effect of ovariectomy and E 2were observed in the rats; the MAO activity was assayed by spectrophotometrically in respective brain areas: frontal cortex and hippocampus, and the effect of E 2 on the MAO activity was examined. ResultsAfter Ovariectomy(OVX) for 6 weeks, the escape latency of the OVX group was significantly increased than that in the Sham group (P< 0.05),and the frequency of memory in the OVX group was significantly decreased(P< 0.05).A significantly increase in MAO activity was found the hippocampus in the OVX group (P<0.01).Replacement therapy for 5weeks,the E 2group showed a significantly change in the escape latency and the frequency of memory as compared with the OVX group(P< 0.05,P< 0.01), and the MAO activity was significantly decreased in the hippocampus(P< 0.01).Conclusion17β-estradiol significantly improved the decrease of spatial learning and memory that was induced by OVX.This effect may correlate with the decrease of the MAO activity in brain.