穹窿-海马伞切断与卵巢切除对大鼠不同脑区酪氨酸激酶A表达的影响

Expression of tyrosine kinase A in different sections of rat＇ s brain with the fimbria/fornix transection and ovariectomy

目的 观察穹窿海马伞切断与卵巢切除对大鼠脑内酪氨酸激酶A（tyrosine kinase A,TrkA）表达的影响。方法 实验于2003年03月至2003年12月在青岛大学医学院附属医院脑病防治重点实验室完成。成年健康雌性Wistar大鼠28只,按2×2方差分析的方法设计,随机分为穹窿-海马伞切断（FF）组、卵巢切除（OVX）组、穹窿-海马伞切断加卵巢切除（OF）组、对照组,每组7只。穹窿海马伞切断参照Klein等的方法,双侧卵巢切除参照Singh等的方法进行。对照组除不切断卵巢和穹窿-海马伞外,其余步骤同模型组。免疫细胞化学染色法观察皮质区、海马CA1区、杏仁复合体区、基底前脑Meynert核等部位TrkA阳性细胞表达变化。数据分析按2×2方差分析的方法进行统计学比较。结果 双侧卵巢切除和双侧穹窿海马伞切断存在显著的主效应和交互效应（P〈0.01）。OVX组、FF组和OF组大鼠大脑皮质区、海马CA1区、杏仁复合体区TrkA表达的阳性细胞数明显减少,与对照组比较差异均有显著性[如皮质区分别为：（16.63±6.12）,（18.91±6.27）,（23.34±6.92）vs（54.77±11.84）,P〈0.01]。其中OF组大鼠海马CA1区TrkA表达的阳性细胞数较FF组和OVX组明显减少,差异有显著性[（7.97±2.00）vs（15.17±5.23）,（24.09±3.79）,F=11,577,98.982,P〈0.01]。结论 穹窿-海马伞切断和/或卵巢切除存在显著的主效应和交互效应,可致大鼠脑内多部位TrkA表达减少,可能与阿尔茨海默病的病理过程有关。

Objective To discuss expressive variety of tyrosine kinase A （TrkA） in different sections of rats＇s brain with fimbria/fornix transection and ovariectomy. Methods Healthy female Wistar rats were randomly divided into 4 groups according to 2 × 2 ANOVA design ：①fimbria/fornix transection of group （ FF ） ; ②ovariectomized group（OVX） ;③fimbria/fornix transection and ovariectomized group （OF） ;④control group. There were seven rats in every group. The bilateral fimbria-fornix of brain were transected according Klein＇ s methods and bilateral ovaries were ablated according Sing＇ s methods in order to erect animal model. Immunoreactive cells of TrkA were stained by immunohistochemical way and observed the expressive varieties of TrkA immunoreactive cell in the cerebral cortex, hippocampus CA1, almond complex and Meynert nucleus. The number of masculine cell were noted with microscope at random selected 5 fields in every detected area, and then compared the average amounts of TrkA according to 2 × 2 ANOVA analysis among the four groups. Results The bilateral fimbria/fornix transection and ovariectomization had an interaction on the expression of TrkA in cerebral cortex, hippocampus CA1, almond complex areas （ P〈 0.01 ）. The expression of TrkA remarkably decreased in hippocampus CA1, cerebral cortex, almond complex and Meynert nucleus of the brain in the FF group, OVX group, and OF group（ for example cortex： 16.63 ±6.12,18.91±6.27,23.34 ±6.92 vs 54.77 ± 11.84, P〈0.01 ） , and especially the expression of TrkA remarkably decreased in hippocampus CA1 of the brain in the OF group with the bilateral fimbria/fornix transection and ovariectomization（ 7. 97 ±2.00 vs 15.17 ±5.23,24.09 ±3.79, P〈0.05）. Conclusion The expres- sion of TrkA protein was decreased in many sections of the brain in rats with fimbria/fornix transection and ovariectomization. Possibly it is a main reason leading to the injury of cognition and Alzheimer＇ s disease.