Effect of exercise training on salivary gland through parasympathetic nervous system

目的：通过副交感神经系统观察运动训练对唾液腺的影响。材料与方法：32周龄雄性ICR小鼠，体重39~50g，随机分为3组：限食组(EXP)、非限食组(EXA)和对照组(CTL)。EXP组采用自愿转轮进行运动，与CTL组饲喂等量日粮(配对喂养)。在运动开始后4、8和12周，用微型吸管从口腔收集毛果芸香碱刺激的全唾液，进行配对喂养。测定唾液流率、蛋白质浓度、淀粉酶和激肽释放酶活性。激肽释放酶和淀粉酶的释放分别由α和β肾上腺素能受体刺激。结果：实验开始后4~12周，EXP小鼠的体重比CTL小鼠轻约20%(p&lt；0.05)。试验组唾液8-OHdG明显升高。实验开始后4~12周，实验组小鼠唾液总蛋白分泌和激肽释放酶活性较对照组下降20~30%(p&lt；0.05~0.01)。结论：运动和饮食控制相结合降低了小鼠唾液激肽释放酶活性，提示运动小鼠唾液腺∂交感神经系统信号转导下调或激肽释放酶合成减少。这种下调被认为是由于8-OHdG的增加。本研究提示，充足的食物摄入量是维持体育锻炼中口腔功能的必要条件。

Objective : The objective of the present study was to examine the effect of exercise training on salivary gland through parasympathetic nervous system.Materials and methods: Male ICR mice, weighing 39〜50g, at 32 weeks of age were divided into three groups; an exercise with food restriction (EXP), an exercise without food restriction (EXA), and a control (CTL). EXP group uses voluntary running wheel for exercise, and fed the same amount of diet as the CTL group (pair-feeding). The pilocarpine stimulated whole saliva was collected from the oral cavity by micro-pipet over 15 min 4, 8, and 12 weeks after beginning of the exercise with pair-feeding. The salivary flow rate, protein concentration, and amylase and kallikrein activities were determined. Kallikrein and amylase release are evoked by alpha- and beta- adrenergic receptor stimulation, respectively.Results: The body weight of EXP mice was approximately 20% less than that of CTL mice between 4 and 12 weeks after the beginning of the experiment (p<0.05). Salivary 8-OHdG was significantly increased in the EXP group. The total protein secretion and kallikrein activity decreased 20〜30% in the EXP mice between 4 and 12 weeks after the starting of experiments when compared with the CTL mice(p<0.05〜0.01).Conclusion : The results showed that the combination of exercise and diet control decreased kallikrein activity from the mice saliva, suggesting that signal transduction in the ∂-sympathetic nervous system was down regulated or the synthesis of kallikrein decreased in the salivary glands of exercise mice. The down-regulation was thought to be due to increse of 8-OHdG. This study suggested that the sufficient food intake was necessary for maintaining the oral function during physical exercise.