Leucine-induced promotion of post-absorptive EAA utilization and hepatic gluconeogenesis contributes to protein synthesis in skeletal muscle of dairy calves
Leucine-induced promotion of post-absorptive EAA utilization and hepatic gluconeogenesis contributes to protein synthesis in skeletal muscle of dairy calves
复制标题
亮氨酸诱导促进吸收后 EAA 利用和肝糖异生有助于奶牛骨骼肌中的蛋白质合成
DOI：
10.1111/jpn.13072
复制
发表时间：
2019
影响因子：
2.7
通讯作者：
Cai Chuanjiang
中科院分区：
文献类型：
--
作者：
Zheng Chen;Yao Junhu;Guo Long;Cao Yangchun;Liang Ziqi;Yang Xinjian;Cai Chuanjiang
犊牛骨骼肌蛋白质合成率高，有利于其第一次泌乳甚至终生产奶。由于蛋白质合成速率在吸收后状态相对较低，本研究的目的是确定补充亮氨酸是否可以增加骨骼肌吸收后必需氨基酸（EAA）的利用和蛋白质合成。将10头雄性新生乳牛（38 ± 3 kg）随机分配至对照组（CON，无亮氨酸补充，n= 5）或补充1.435 g亮氨酸/L牛奶（LEU，n= 5）。结果表明，亮氨酸显著增加了背最长肌（LD）的长度和蛋白质浓度，而降低了肌酐浓度和谷氨酰胺乙酸转氨酶（GOT）活性。与对照组相比，补充亮氨酸还降低了谷丙转氨酶（GPT）活性。补充亮氨酸可改善哺乳动物雷帕霉素靶蛋白（mTOR）、真核起始因子4 E结合蛋白1（4 EBP 1）和底物核糖体蛋白S6激酶1（p70 S6 K）的磷酸化。补充亮氨酸可使血清中葡萄糖、蛋氨酸、苏氨酸、组氨酸和必需氨基酸浓度升高，精氨酸浓度降低。与CON相比，LEU中肝脏葡萄糖浓度较高，吡喃酸较低。总之，亮氨酸补充可以促进吸收后EAA利用和肝脏再生，这有助于乳牛骨骼肌中的蛋白质合成。
The high rate of protein synthesis in skeletal muscle of dairy calves can benefit their first lactation even lifetime milk yield. Since the rate of protein synthesis is relatively low in the post‐absorptive state, the aim of this research was to determine whether leucine supplementation could increase the post‐absorptive essential amino acid (EAA) utilization and protein synthesis in the skeletal muscle. Ten male neonatal dairy calves (38 ± 3 kg) were randomly assigned to either the control (CON, no leucine supplementation,n= 5) or supplementation with 1.435 g leucine/L milk (LEU,n= 5). Results showed that leucine significantly increased the length and protein concentration in longissimus dorsi (LD) muscle, whereas it decreased creatinine concentration and glutamic‐oxalacetic transaminase (GOT) activity. Compared to the control group, leucine supplementation also reduced the glutamic‐pyruvic transaminase (GPT) activity. Supplementation of leucine improved the phosphorylation of mammalian target of rapamycin (mTOR), eukaryotic initiation factor 4E‐binding protein 1 (4EBP1) and substrates ribosomal protein S6 kinase 1 (p70S6K). Supplementation of leucine resulted in increased concentrations of glucose, methionine, threonine, histidine and EAAs and decreased concentration of arginine in serum. Liver glucose concentration was higher and pyranic acid was lower in LEU compared to CON. In conclusion, leucine supplementation can promote post‐absorptive EAA utilization and hepatic gluconeogenesis, which contributes to protein synthesis in skeletal muscle of dairy calves.