中等负荷运动对慢性心理应激大鼠淋巴细胞数量和Th1/Th2平衡的影响

背景:已有研究证实应激能够影响免疫功能,干扰机体的内环境稳态,而适宜运动在一定程度上能减轻不良心理应激反应.目的:观察中等负荷运动对慢性心理应激大鼠脾和肠系膜淋巴结淋巴细胞数量、血清干扰素Y和白细胞介素4水平以及Thl/Th2细胞平衡的影响.设计、时间及地点:随机对照动物实验,于2007～05/10在成都体育学院运动人体科学省级重点实验室完成.材料:40只健康雄性SD大鼠按随机数字表分为4组:对照组、心理应激组、运动组、运动+心理应激组,每组10只.方法:运动组、运动+心理应激组于实验前进行适应性游泳训练,30 min/(次·d),共3 d,实验时无负重游泳60 min,(次·d),总运动时间8周.运动+应激组在8周运动结束1 d后,开始21 d慢性束缚应激,6 h/d;心理应激组于同一时间点建立慢性束缚应激模型;运动组大鼠在8周运动结束后,同期饲养22 d;对照组大鼠同期饲养,不进行任何干预.主要观察指标:检测大鼠脾和肠系膜淋巴结淋巴细胞数量,并以ELISA法检测血清干扰素γ和白细胞介素4水平以及干扰素γ/白细胞介素4比值变化.结果:与对照组比较,心理应激组脾和肠系膜淋巴结淋巴细胞数量明显降低,血清干扰素γ及干扰素γ/白细胞介素4比值显著下降(P<0.01),Th1/Th2平衡失调.与心理应激组比较,运动+心理应激组淋巴细胞数量明显增加,干扰索γ水平和干扰素γ/白细胞介素4比值明显增高(P<0.05).与对照组比较,运动组脾和肠系膜淋巴结淋巴细胞数量虽无显著差异,但有上升趋势.运动+应激组与运动组及对照组比较,3组血清干扰素γ水平、干扰素γ,白细胞介素4比值差异无显著性意义.结论:中等负荷运动可明显增加慢性心理应激状态下脾和肠系膜淋巴结淋巴细胞数量,通过上调干扰素γ水平调节Th1/Th2的失衡,维持机体的免疫稳态.

Effects of moderate exercise on lymphocyte number and Th1/Th2 balance in rats under chronic psychological stress

BACKGROUND: Previous studies have proved that stress can affect immunity function and disturb homeostasis of bodies. Moderate exercise can alleviate the psychological stress reaction to some degree.OBJECTIVE: To observe the effects of moderate exercise on lymphocyte number in spleen and mesenteric lymph nod,interferon-y (IFN-γ) and interleukine-4(IL-4) level in serum, as well as Th1/Th2 balance in rats under chronic psychological stress.DESIGN, TIME AND SETTING: A randomized control animal experiment was carried out in the laboratory of Sports Human Science in Chengdu Sports University from May to October in 2007.MATERIALS: A total of 40 healthy male SD rats were divided by random digits table into 4 groups: control group, psychological stress group, exercise group and exercise+psychological stress group, with 10 ones in each group.METHODS: Before experiment, rats in exercise group and exercise+psychological stress group underwent 3 days of adaptive swimming training, 30 min/(t·d). During experiment, they were made swimming with no weight loading for 8 weeks, 60 min/(t·d).From day 2 post exercise on, rats in exercise+psychological stress group began to undergo the 21 days of chronic restraint stress,6 hours per day. At the same time, the chronic restraint stress models were established in the psychological stress group. Rats in the exercise group were fed for 22 days since the 8~(th) day of exercise ended. Rats in the control group were only fed without any intervention.MAIN OUTCOME MEASURES: The lymphocyte number in spleen and mesenteric lymph node was measured, and ELISA was employed to measure IFN-y and IL-4 levels as well as the ratio of IFN-y/IL-4 in serum.RESULTS: Compared with the control group, the lymphocyte number, the level of IFN-y and the ratio of IFN-y/IL-4 were significantly decreased in psychological stress group (P < 0.01 ), and the Thlf'rh2 balance was broken. Compared with the psychological group, the exercise+psychological stress group had got significantly higher lymphocyte number, IFN-γ level and ratio of IFN-γ/IL-4 (P<0.05). The lymphocyte number in spleen and mesenteric lymph node in the exercise group showed not a difference of significance compared with the control group, but a tendency towards going up. There was no difference of significance in IFN-γ level and ratio of IFN-γ/IL-4 among the exercise+psychological stress group, the exercise group and the control group.CONCLUSION: Moderate exercise can increase lymphocyte number in spleen and mesenteric lymph node significantly,up-regulate the IFN-γ level so as to regulate the disbalance of Th1/Th2, and maintain immunity homeostasis.