Effect of exercise training on salivary gland through parasympathetic nervous system

目的：本研究的目的是通过副交感神经系统检查运动训练对唾液腺的影响。材料和方法：雄性ICR小鼠，体重39 ~ 50 g，32周龄，分为三组：运动与食物限制（EXP），运动与食物限制（EXA），和对照（CTL）。EXP组采用自行跑轮进行运动，饲喂与CTL组相同量的饲料（成对饲喂）。在配对喂养的运动开始后的第4、8和12周，用微量移液管从口腔收集毛果芸香碱刺激的全唾液，持续15分钟。测定唾液流速、蛋白质浓度、淀粉酶和激肽释放酶活性。结果：实验开始后4 - 12周，EXP小鼠的体重比CTL小鼠的体重轻约20%（p<0.05）。EXP组唾液8-OHdG显著增加。与CTL小鼠相比，在实验开始后4 - 12周，EXP小鼠的总蛋白分泌和激肽释放酶活性降低了20 - 30（p<0.05 ~ 0.01）。结果表明，运动和饮食控制的结合降低了小鼠唾液中的激肽释放酶活性，提示运动小鼠唾液腺中交感神经系统的信号转导下调或激肽释放酶的合成减少。这种下调被认为是由于8-OHdG的增加。本研究提示，运动时充足的食物摄入是维持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.