β-羟基-β-甲基丁酸促进去卵巢小鼠超负荷诱导的骨骼肌蛋白质合成  

β-HYDROXY-β-METHYLBUTYRATE PROMOTES PROTEIN SYNTHESIS OF THE OVERLOADED SKELETAL MUSCLE IN OVARIECTOMIZED MICE

作　　者：于芳芳 李涛 李婷婷 王海微 蒋晓桐 丁琳 史仍飞 YU Fang-fang;LI Tao;LI Ting-ting;WANG Hai-wei;JIANG Xiao-tong;DING Lin;SHI Reng-fei(School of Sports Health,Shanghai University of Sport,Shanghai 200438,China)

机构地区：[1]上海体育大学运动健康学院,上海200438

出　　处：《营养学报》2024年第4期334-339,共6页Acta Nutrimenta Sinica

基　　金：国家自然基金面上项目(No.32171136);上海自然科学基金资助项目(No.19ZR1452900);国家重点研发项目子课题(No.2020YFC2005604)。

摘　　要：目的探讨补充β-羟基-β-甲基丁酸(β-hydroxy-β-methylbutyrate,HMB)对去卵巢小鼠骨骼肌代偿性肥大的影响及其可能机制。方法对16只成年雌性C57小鼠(8 w)进行去卵巢手术,术后1 w施行右后肢腓肠肌远端腱切术,超负荷诱导骨骼肌肥大(overload,Ovld侧),另一侧行假手术(Sham侧),随机分为对照组(n=8)和HMB补充组(n=8)。HMB补充采用灌胃方式,0.5 g/kg,每天1次,对照组灌胃等量生理盐水,共7 d,干预前后称量体重,使用Echo MRI检测体成分。取材前18h腹腔注射嘌呤霉素0.04μmol/g体重。取跖肌并称量,采用蛋白印迹技术检测骨骼肌mTOR、S6、Akt蛋白及其磷酸化水平的表达和蛋白质合成率。结果实验干预后,组内小鼠Ovld侧与Sham侧相比,跖肌质量显著性增加(P<0.01);p-mTOR/mTOR、p-S6/S6、p-Akt/Akt比值均增加,且在HMB组中p-mTOR/mTOR、p-S6/S6比值显著增加(P<0.05);蛋白质合成率均增加,但仅在HMB组中显著性增加(P<0.05)。与对照组相比,HMB组干预后跖肌质量均显著增加(P<0.01),体脂比率降低但无显著性差异(P>0.05);HMB组同侧肌肉p-mTOR/mTOR、p-S6/S6、p-Akt/Akt比值均增加,但仅有p-mTOR/mTOR、p-S6/S6有显著性差异(P<0.05);HMB组蛋白质合成率均显著性增加(P<0.05)。结论HMB通过调控mTOR、S6蛋白质合成信号与腓肠肌远端腱切术共同促进骨骼肌肥大,并提高蛋白质合成率。Objective To investigate the effect ofβ-hydroxy-β-methylbutyrate(HMB)supplementation on compensatory hypertrophy of skeletal muscle in ovariectomized mice and its possible mechanism.Methods Sixteen adult female C57 mice were subjected to ovarian removal surgery.After a week,they were treated with distal tenotomy of gastrocnemius muscle in the right hind limb,resulting in overloaded skeletal muscle hypertrophy(overload,Ovld side),and the other side underwent the sham surgery(Sham side).They were randomly divided into control group(n=8)and HMB supplementation group(n=8).HMB was supplemented by intragastric administration(0.5 g/kg)once a day.The control group was given the same amount of normal saline.The experiment lasted for 7d.Before and after the intervention,the body weight was recorded and the body composition was measured by Echo MRI.The mice were intraperitoneally injected with puromycin(0.04μmol(/g·bw))18h before extraction.The plantaris muscle was taken and weighed.The protein expression of mTOR,S6,Akt and their phosphorylation levels and protein synthesis rate were measured by western blotting.Results After the intervention,compared with the Sham side,the muscle mass of plantaris in the Ovld side increased significantly(P<0.01).The relative expression of p-mTOR/mTOR,p-S6/S6 and p-Akt/Akt in the plantaris muscle of Ovld side increased,and p-mTOR/mTOR and p-S6/S6 increased significantly in the HMB group(P<0.05).The protein synthesis rate of the plantaris muscle in the Ovld side was increased,with a significant increase in the HMB group(P<0.05).Compared with the control group,the muscle mass of plantaris on both sides was significantly increased in the HMB group(P<0.01),and the body fat percentage reduced without a significant difference(P>0.05).The ratios of p-mTOR/mTOR,p-S6/S6 and p-Akt/Akt of the ipsilateral muscle were increased in the HMB group,but only the p-mTOR/mTOR and p-S6/S6 ratios had a significant difference(P<0.05).The protein synthesis rate in the HMB group was significantly increased(P<0.

关 键 词：HMB 去卵巢 骨骼肌肥大 蛋白质合成率 

分 类 号：G804.7[文化科学—运动人体科学]