中枢运动性疲劳应激大鼠下丘脑腹内侧核和背内侧核神经元中一氧化氮合酶的表达

背景运动性疲劳作为一种应激源,必然会引起脑内某些神经核团物质和功能的变化,哪些核团与运动性疲劳关系密切,哪些物质介导了疲劳的中枢神经功能和/或结构的改变,目前尚不清楚.目的研究下丘脑腹内侧核和背内侧核神经元中一氧化氮合酶与运动性疲劳的关系.设计随机对照实验.材料实验于2003-10/2004-01在中北大学和山西医科大学人体解剖学教研室完成.选择雄性Wister大鼠20只,清洁级.干预动物随机分为实验组10只,对照组10只.实验组每天经大运动量游泳达到力竭状态,并连续4周,制成运动性疲劳动物模型.造模完成后用ABC免疫组织化学方法观测下丘脑腹内侧核和背内侧核神经元中神经元型一氧化氮合酶表达状况,并进行图像分析和统计学处理.主要观察指标单位视野中神经元型一氧化氮合酶阳性细胞个数、阳性物面积和灰度.结果疲劳组下丘脑腹腔内侧核中神经元型一氧化氮合酶阳性细胞数量为(25.25±7.35)个/视野,显著大于对照组(9.70±3.20)个/视野(P＜0.001);神经元型一氧化氮合酶阳性物面积为(3 867.75±1 940.41)μm2/视野,显著大于对照组(750.13±579.88)μm2/视野(P＜0.001);疲劳组背内侧核中神经元型一氧化氮合酶阳性细胞数量为(30.25±7.87)个/视野,显著大于对照组(14.00±4.99)个/视野(P＜0.001);神经元型一氧化氮合酶阳性物面积为(4 512.06±1 243.93)μm2/视野,显著大于对照组(782.46±711.46)μm2/视野(P＜0.001).结论下丘脑腹内侧核和背内侧核神经元中的神经元型一氧化氮合酶阳性神经元与中枢运动性疲劳的形成密切相关,一氧化氮可能在下丘脑腹内侧核和背内侧核对疲劳应激反应的调节中发挥重要作用.

Expression of nitric oxide synthase in ventromedial hypothalamic nucleus and dorsomedial hypothalamic nucleus of rats under stress of central exercise-induced fatigue

BACKGROUND:As a kind of stressor, exercise-induced fatigue surely can lead to the material and functional changes of certain nerve nucleus within brain.It is still uncertain on what kind of nucleus closely relate to exer-cise-induced fatigue and what materials induce the functional or/and structural changes of tired central nerve.OBJECTIVE:To study the relationship between nitric oxide synthase (NOS) in ventromedial hypothalamic nucleus(VMH),dorsomedial hypothalamic nucleus(DMH) and exercise-induced fatigue.DESIGN:Randomized controlled study.MATERIALS:The experiment was completed in the Department of Human Anatomy of North University of China and Shanxi Medical University during October 2003 to January 2004.Twenty male Wister rats of clean class were selected.INTERVENTIONS:The rats were randomly divided into experimental group and control group with each of 10 rats.The rats in experimental group were made exercise-induced fatigue animal model by doing heavy load swimming until they were exhausted for 4 consecutive weeks. After the model was built,ABC immunohistochemical method was used to observe the expression of neuronal NOS (nNOS) in neurons of VMH ,and DMH and image analysis and statistic process were conducted.MAIN OUTCOME MEASURES:Number of nNOS positive cells in per unit visual field; Area and gray of positive substance.RESULTS:The number of nNOS positive cells in VMH of fatigue group was (25.25±7.35)/visual field which was much greater than that of control group (9.70±3.20)/visual field(P＜ 0.001).The area of nNOS positive substance was (3 867.75±1 940.41)μm2/visual field which was greater than that of control group(750.13±579.88)μm2/visual field(P ＜ 0.001). The number of nNOS positive cells in DMH of fatigue group was (30.25±7.87) /visual field which was much greater than that of control group (14.00±4.99) /visual field. And the area of nNOS positive substance was (4 512.06±1 243.93) μm2/visual field that was much greater than that of control group(782.46±711.46)μm2/visual field(P ＜ 0.001).CONCLUSION:The nNOS positive neurons in VMH and DMH neurons are closely related to the occurrence of central exercise-induced fatigue.Nitric oxide may play an important role in regulation of VMH and DMH to stress caused by fatigue.