Matsuo Kaori, Sato Koji, Suemoto Ken, Miyamoto-Mikami Eri, Fuku Noriyuki, Higashida Kazuhiko, Tsuji Katsunori, Xu Yuzhong, Liu Xin, Iemitsu Motoyuki, Hamaoka Takafumi, Tabata Izumi
1Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, JAPAN; 2Faculty of Health and Sports Science, Juntendo University, Inzai, Chiba, JAPAN; and 3Department of Food Science and Nutrition, The University of Shiga Prefecture, Hikone, Shiga, JAPAN.
Med Sci Sports Exerc. 2017 Sep;49(9):1805-1816. doi: 10.1249/MSS.0000000000001312.
We examined effects of high-intensity training on chemically induced aberrant crypt foci (ACF) in rat colon. We also investigated mechanisms that may underlie the results obtained, with a focus on secreted protein acidic and rich in cysteine (SPARC), which has been proposed as an exercise-related factor of colon cancer prevention.
After an administration of 1,2-dimethylhydrazine, F344 rats executed high-intensity intermittent swimming training (HIIST) (twelve 20-s swimming with a weight [16% body weight] with 10-s pauses between the bouts) 5 d·wk for 4 wk. The acute and chronic effects of the HIIST on SPARC were evaluated in rats. We evaluated the in vitro and in vivo effects of 5' AMP-activated protein kinase (AMPK) activator on SPARC in rat serum and epitrochlearis muscle. In human subjects, we determined serum SPARC after exhaustive bicycling consisting of six to seven bouts of exercise at 170% V˙O2max with 10-s rests between the bouts (high-intensity intermittent bicycling [HIIB]). The SPARC mRNA in human vastus lateralis was measured before and after the HIIB for 4 d·wk for 6 wk (HIIB-training [HIIBT]).
The numbers of ACF were lower in the HIIST (47 ± 22) compared with the control (122 ± 47) rats (P < 0.05). SPARC in epitrochlearis and serum after HIIS of the trained rat was higher than that in the control resting rats. In vitro and vivo AMPK stimulation increased mRNA and SPARC protein in rat epitrochlearis, respectively. The human serum SPARC after the HIIB was elevated. SPARC mRNA in human muscle was elevated after the HIIBT.
The results demonstrated that HIIST inhibits 1,2-dimethylhydrazine-induced colon ACF development. This effect may be explained by SPARC induction by the exercise intensity-related factor AMPK, potentially explaining the preventive effects of high-intensity intermittent exercise training against colon cancer.
我们研究了高强度训练对大鼠结肠化学诱导的异常隐窝病灶（ACF）的影响。我们还研究了可能导致所得结果的机制，重点关注富含半胱氨酸的酸性分泌蛋白（SPARC），它被认为是与运动相关的预防结肠癌的因素。
给予1,2 - 二甲基肼后，F344大鼠进行高强度间歇游泳训练（HIIST）（十二次20秒游泳，负重[体重的16%]，每次间歇10秒），每周5天，共4周。评估HIIST对大鼠SPARC的急性和慢性影响。我们评估了5' AMP激活蛋白激酶（AMPK）激活剂对大鼠血清和肱三头肌中SPARC的体外和体内作用。在人类受试者中，我们测定了在进行由六到七组运动组成的力竭性骑行后血清中的SPARC，每组运动强度为最大摄氧量（V˙O2max）的170%，每组间歇10秒（高强度间歇骑行[HIIB]）。在进行HIIB训练（HIIBT）4周，每周6天，共6周前后，测量人类股外侧肌中的SPARC mRNA。
与对照组（122 ± 47）大鼠相比，HIIST组（47 ± 22）的ACF数量更低（P < 0.05）。训练大鼠进行HIIS后，肱三头肌和血清中的SPARC高于对照组静息大鼠。体外和体内AMPK刺激分别增加了大鼠肱三头肌中的mRNA和SPARC蛋白。HIIB后人类血清中的SPARC升高。HIIBT后人类肌肉中的SPARC mRNA升高。
结果表明，HIIST可抑制1,2 - 二甲基肼诱导的结肠ACF发展。这种效应可能由运动强度相关因子AMPK诱导的SPARC来解释，这可能解释了高强度间歇运动训练对结肠癌的预防作用。
