武汉体育学院学报
武漢體育學院學報
무한체육학원학보
Journal of Wuhan Institute of Physical Education
2014年
9期
94~100
,共null页
夏志 赵艳 尚画雨 叶菊菲 杨力源 苏全生 熊伟平
夏誌 趙豔 尚畫雨 葉菊菲 楊力源 囌全生 熊偉平
하지 조염 상화우 협국비 양력원 소전생 웅위평
亮氨酸 丙氨酸 血浆游离氨基酸 氨基酸转运蛋白
亮氨痠 丙氨痠 血漿遊離氨基痠 氨基痠轉運蛋白
량안산 병안산 혈장유리안기산 안기산전운단백
leucine; alanine; plasma free amino acld; amino acid transporter
目的:探讨补充亮氨酸对老年前期小鼠血浆游离氨基酸的影响及其可能机制.方法:13月龄小鼠分别给予5%亮氨酸和3.4%丙氨酸添加8周.血糖仪测血糖,ELISA法测血清胰岛素,氨基酸分析仪测血浆氨基酸谱,RT-PCR测腓肠肌氨基酸转运蛋白LAT1、CD98、PAT1、SNAT2与GCN2基因表达,BCA法蛋白定量,免疫印迹法测mTOR磷酸化率.结果:亮氨酸添加未致血糖、胰岛素水平显著变化;氨基酸谱仅亮氨酸含量显著增加,丙氨酸、谷氨酸、甘氨酸含量显著下降,其他氨基酸水平无差异;LAT1、CD98基因表达显著上调,其他表达未见差异;肌肉蛋白总量与mTOR磷酸化率均显著增加.结论:膳食添加亮氨酸通过增加血浆游离亮氨酸含量活化LAT1、CD98,增加胞内氨基酸可利用性并与mTOR关联,促进肌肉蛋白合成.
目的:探討補充亮氨痠對老年前期小鼠血漿遊離氨基痠的影響及其可能機製.方法:13月齡小鼠分彆給予5%亮氨痠和3.4%丙氨痠添加8週.血糖儀測血糖,ELISA法測血清胰島素,氨基痠分析儀測血漿氨基痠譜,RT-PCR測腓腸肌氨基痠轉運蛋白LAT1、CD98、PAT1、SNAT2與GCN2基因錶達,BCA法蛋白定量,免疫印跡法測mTOR燐痠化率.結果:亮氨痠添加未緻血糖、胰島素水平顯著變化;氨基痠譜僅亮氨痠含量顯著增加,丙氨痠、穀氨痠、甘氨痠含量顯著下降,其他氨基痠水平無差異;LAT1、CD98基因錶達顯著上調,其他錶達未見差異;肌肉蛋白總量與mTOR燐痠化率均顯著增加.結論:膳食添加亮氨痠通過增加血漿遊離亮氨痠含量活化LAT1、CD98,增加胞內氨基痠可利用性併與mTOR關聯,促進肌肉蛋白閤成.
목적:탐토보충량안산대노년전기소서혈장유리안기산적영향급기가능궤제.방법:13월령소서분별급여5%량안산화3.4%병안산첨가8주.혈당의측혈당,ELISA법측혈청이도소,안기산분석의측혈장안기산보,RT-PCR측비장기안기산전운단백LAT1、CD98、PAT1、SNAT2여GCN2기인표체,BCA법단백정량,면역인적법측mTOR린산화솔.결과:량안산첨가미치혈당、이도소수평현저변화;안기산보부량안산함량현저증가,병안산、곡안산、감안산함량현저하강,기타안기산수평무차이;LAT1、CD98기인표체현저상조,기타표체미견차이;기육단백총량여mTOR린산화솔균현저증가.결론:선식첨가량안산통과증가혈장유리량안산함량활화LAT1、CD98,증가포내안기산가이용성병여mTOR관련,촉진기육단백합성.
The objective of this study was to investigate the effect of leucine supplementation on plasma free amino acids in pre--senile mice and the possible mechanism. Thirteen-month-old mice were treated with normal chow diet supplemented with 5% leucine and 3.4% alanine respectively for 8 weeks. The blood glucose was determined with a portable blood glu- cose meter, serum insulin concentration was determined by ELISA. Plasma free amino acids were determined with an ami- no acid analyzer, mRNA expression of LAT1, CD98, PAT1, SNAT2 and GCN2 were evaluated by Real-time quantitative RT-PCR. BCA method was used to detect the gastrocnemius protein content. Phosphorylation rate of mammalian target of rapamycin (roTOR) were detected by the method of Western blotting. The results showed that leueine supplementation did not change the level of blood glucose and serum insulin. The content of leucine increased significantly but alanine, glu- tamic acid and glycine dropped dramatically. Other amino acids were unchanged. As for the mRNA expression, lustLAT1 and CD98 elevated significantly while the others were unchanged. The protein content and phosphorylation rate of mTOR in gastrocnemius were both significantly in- creased. It could be concluded that diet leucine supplemen- tation elevated amino acids availability in skeletal muscle cells through the activated LAT1 and CD98 which were in- fluenced by increased plasma free leucine. Meanwhile, these two amino acid transporters, coupled with the activa- tion of roTOR and finally promoted the protein synthesis inskeletal muscle.