Kido Kohei, Sato Koji, Makanae Yuhei, Ato Satoru, Hayashi Tadahiro, Fujita Satoshi
Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan.
R&D Center, Kobayashi Pharmaceutical Co., Ltd., Ibaraki, Osaka, Japan.
Nutrition. 2016 Jan;32(1):108-13. doi: 10.1016/j.nut.2015.06.015. Epub 2015 Jul 22.
Kamishimotsuto (KST) is a supplement containing 13 different herbs including Phellodendron bark, Anemarrhena rhizome and ginseng that have been shown to activate mammalian target of rapamycin complex 1 (mTORC1) and thereby increase muscle protein synthesis in vitro. However, the combined effect of KST and resistance exercise on muscle protein anabolism has not been investigated in vivo. Therefore, the purpose of this study was to investigate the effect of KST supplementation, resistance exercise on (mTORC1) signaling and subsequent muscle protein synthesis.
Male Sprague-Dawley rats were divided into two groups: one group received KST (500 mg/kg/d in water) and the other group received placebo (PLA) for 7 d. After 12 h of fasting, the right gastrocnemius muscle was isometrically exercised via percutaneous electrical stimulation. Muscle samples were analyzed for muscle protein synthesis (MPS) and by western blotting analysis to assess the phosphorylation of p70S6K (Thr389), rpS6 (Ser240/244), and Akt (Ser473 and Thr308).
KST supplementation for 7 d significantly increased basal p-Akt (Ser473) levels compared with PLA, phosphorylation of the signaling proteins and MPS at baseline were otherwise unaffected. p-p70S6K and p-rpS6 levels significantly increased 1 h and 3 h after exercise in the PLA group, and these elevations were augmented in the KST group (P < 0.05). Furthermore, MPS at 6 h after resistance exercise was greater in the KST group than in the PLA group (P < 0.05).
While resistance exercise alone was able to increase p70S6K and rpS6 phosphorylation, Kamishimotsuto supplementation further augmented resistance exercise-induced muscle protein synthesis through mTORC1 signaling.
加味柴胡桂枝干姜汤（KST）是一种含有黄柏、知母和人参等13种不同草药的补充剂，已被证明能激活雷帕霉素复合物1（mTORC1）的哺乳动物靶点，从而在体外增加肌肉蛋白质合成。然而，KST与抗阻运动对肌肉蛋白质合成代谢的联合作用尚未在体内进行研究。因此，本研究的目的是探讨补充KST、抗阻运动对（mTORC1）信号传导及随后肌肉蛋白质合成的影响。
将雄性Sprague-Dawley大鼠分为两组：一组给予KST（500mg/kg/d溶于水中），另一组给予安慰剂（PLA），持续7天。禁食12小时后，通过经皮电刺激对右侧腓肠肌进行等长运动。对肌肉样本进行肌肉蛋白质合成（MPS）分析，并通过蛋白质免疫印迹分析评估p70S6K（Thr389）、rpS6（Ser240/244）和Akt（Ser473和Thr308）的磷酸化情况。
与PLA组相比，补充KST 7天显著提高了基础p-Akt（Ser473）水平，其他方面，信号蛋白的磷酸化和基线时的MPS未受影响。PLA组运动后1小时和3小时p-p70S6K和p-rpS6水平显著升高，KST组的这些升高更为明显（P<0.05）。此外，抗阻运动后6小时KST组的MPS高于PLA组（P<0.05）。
虽然单独的抗阻运动能够增加p70S6K和rpS6磷酸化，但补充加味柴胡桂枝干姜汤通过mTORC1信号传导进一步增强了抗阻运动诱导的肌肉蛋白质合成。
