Effects of a soy protein diet on exercise-induced muscle protein catabolism in rats
Effects of a soy protein diet on exercise-induced muscle protein catabolism in rats
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DOI：
10.1016/s0899-9007(02)00744-x
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发表时间：
2002-06-01
期刊：
影响因子：
4.4
通讯作者：
Kishi, K
中科院分区：
文献类型：
--
作者：
Nikawa, T;Ikemoto, M;Kishi, K
目的：我们研究了饮食大豆分离蛋白对大鼠肌肉钙蛋白酶活性和肌球蛋白重链（MHC）降解的影响，进行急性running exercise.METHODS：在大鼠喂20%酪蛋白饮食，跑步机跑步运动，固定在80 kg/rn，短暂增加腓肠肌钙蛋白酶活性，并行肌酸激酶释放到血浆中。固定跑还引起肌肉中MHC免疫反应性降解片段的积累。喂食20%大豆分离蛋白饲料与对照酪蛋白饲料相比，显著抑制了大鼠跑步诱导的mu-和m-钙蛋白酶激活、MHC断裂和肌酸激酶释放到血浆中结果：喂食大豆分离蛋白饮食的大鼠腓肠肌中的钙蛋白酶抑制蛋白活性显著高于喂食酪蛋白饮食的大鼠（P < 0.05），表明这种增加抑制了运动诱导的钙蛋白酶的自激活。蛋白酶体，组织蛋白酶B + L，抗氧化酶和谷胱甘肽和硫代巴比妥酸反应物质在肌肉中的水平的活动没有不同的饮食组之间的exercises.CONCLUSIONS：我们的研究结果表明，饮食中含有大豆蛋白防止运动引起的蛋白质降解骨骼肌，可能通过抑制钙蛋白酶介导的蛋白水解。
OBJECTIVE: We examined effects of dietary soy protein isolate on muscle calpain activity and myosin heavy chain (MHC) degradation in rats performing an acute running exercise.METHODS: In rats fed a 20% casein diet, the treadmill running exercise, fixed at 80 kg/rn, transiently increased calpain activity in gastrocnemius muscles in parallel with the release of creatine kinase into plasma. The fixed running also caused an accumulation of immunoreactive degradation fragments of MHC in the muscle. Feeding a 20% soy protein isolate diet as opposed to the control casein diet to rats significantly suppressed the running-induced activation of mu- and m-calpains, fragmentation of MHC, and release of creatine kinase into plasma (P < 0.05).RESULTS: Rats fed the soy protein isolate diet had significantly higher calpastatin activity in gastrocnemius muscle than did rats fed the casein diet (P < 0.05), indicating that this increase inhibits the exercise-induced autoactivation of calpain. Activities of proteasome, cathepsin B + L, and antioxidant enzymes and the levels of glutathione and thiobarbituric acid-reactive substances in the muscle did not differ between the diet groups at the end of the exercise.CONCLUSIONS: Our results suggest that diets containing soy protein prevent exercise-induced protein degradation in skeletal muscle, possibly through inhibiting the calpain-mediated proteolysis.