体育科学
體育科學
체육과학
SPORT SCIENCE
2015年
6期
49-56
,共8页
夏志%赵艳%尚画雨%叶菊菲%杨力源%孙君志%熊伟平%苏全生
夏誌%趙豔%尚畫雨%葉菊菲%楊力源%孫君誌%熊偉平%囌全生
하지%조염%상화우%협국비%양력원%손군지%웅위평%소전생
亮氨酸%骨骼肌%泛素-蛋白酶体%蛋白质降解%萎缩
亮氨痠%骨骼肌%汎素-蛋白酶體%蛋白質降解%萎縮
량안산%골격기%범소-단백매체%단백질강해%위축
leucine%skeletal muscle%ubiquitin-proteasome%protein degradation%atrophy
目的:探讨膳食补充亮氨酸对增龄所致骨骼肌萎缩的影响及可能机制。方法:13月龄雄性ICR小鼠根据体重随机分为补充亮氨酸(Leu )、补充丙氨酸(Ala )以及空白对照组(NC ),Leu和 Ala组分别在饲料中添加5%比例亮氨酸和3.4%比例丙氨酸8周,NC组饲喂普通饲料。末次给食后禁食17 h处死小鼠,便携式血糖仪检测血糖;ELISA法检测血清胰岛素、IG F‐1;分光光度法检测血尿素氮;氨基酸分析仪检测血浆游离氨基酸谱;H E染色观察肌纤维适应性及病理性改变;BCA 法定量蛋白后,Western Blotting 法检测 Ub、Atrogin‐1、MuRF‐1及M HCⅡ的蛋白表达。结果:与NC组和Ala组小鼠相比,添加5%亮氨酸(Leu组)未显著影响小鼠体重、采食量,血糖、胰岛素水平与IG F‐1无显著变化,血尿素氮水平显著下降;血浆游离亮氨酸含量升高而丙氨酸、甘氨酸和谷氨酸含量下降;腓肠白肌湿重/体重比值、肌纤维横截面积及直径均表现出增长的趋势,但增幅并不显著;骨骼肌纤维圆形化、核中心化病变显著减少;腓肠白肌总蛋白含量、M HCⅡ蛋白表达显著增加,而 Ub、Atrogin‐1及MuRF‐1的蛋白表达均显著下降。Ala组与 NC组小鼠相比各指标差异均无统计学意义。结论:亮氨酸能够削弱老年前期小鼠骨骼肌萎缩,其机制可能与亮氨酸对泛素‐蛋白酶体系统的抑制有关。
目的:探討膳食補充亮氨痠對增齡所緻骨骼肌萎縮的影響及可能機製。方法:13月齡雄性ICR小鼠根據體重隨機分為補充亮氨痠(Leu )、補充丙氨痠(Ala )以及空白對照組(NC ),Leu和 Ala組分彆在飼料中添加5%比例亮氨痠和3.4%比例丙氨痠8週,NC組飼餵普通飼料。末次給食後禁食17 h處死小鼠,便攜式血糖儀檢測血糖;ELISA法檢測血清胰島素、IG F‐1;分光光度法檢測血尿素氮;氨基痠分析儀檢測血漿遊離氨基痠譜;H E染色觀察肌纖維適應性及病理性改變;BCA 法定量蛋白後,Western Blotting 法檢測 Ub、Atrogin‐1、MuRF‐1及M HCⅡ的蛋白錶達。結果:與NC組和Ala組小鼠相比,添加5%亮氨痠(Leu組)未顯著影響小鼠體重、採食量,血糖、胰島素水平與IG F‐1無顯著變化,血尿素氮水平顯著下降;血漿遊離亮氨痠含量升高而丙氨痠、甘氨痠和穀氨痠含量下降;腓腸白肌濕重/體重比值、肌纖維橫截麵積及直徑均錶現齣增長的趨勢,但增幅併不顯著;骨骼肌纖維圓形化、覈中心化病變顯著減少;腓腸白肌總蛋白含量、M HCⅡ蛋白錶達顯著增加,而 Ub、Atrogin‐1及MuRF‐1的蛋白錶達均顯著下降。Ala組與 NC組小鼠相比各指標差異均無統計學意義。結論:亮氨痠能夠削弱老年前期小鼠骨骼肌萎縮,其機製可能與亮氨痠對汎素‐蛋白酶體繫統的抑製有關。
목적:탐토선식보충량안산대증령소치골격기위축적영향급가능궤제。방법:13월령웅성ICR소서근거체중수궤분위보충량안산(Leu )、보충병안산(Ala )이급공백대조조(NC ),Leu화 Ala조분별재사료중첨가5%비례량안산화3.4%비례병안산8주,NC조사위보통사료。말차급식후금식17 h처사소서,편휴식혈당의검측혈당;ELISA법검측혈청이도소、IG F‐1;분광광도법검측혈뇨소담;안기산분석의검측혈장유리안기산보;H E염색관찰기섬유괄응성급병이성개변;BCA 법정량단백후,Western Blotting 법검측 Ub、Atrogin‐1、MuRF‐1급M HCⅡ적단백표체。결과:여NC조화Ala조소서상비,첨가5%량안산(Leu조)미현저영향소서체중、채식량,혈당、이도소수평여IG F‐1무현저변화,혈뇨소담수평현저하강;혈장유리량안산함량승고이병안산、감안산화곡안산함량하강;비장백기습중/체중비치、기섬유횡절면적급직경균표현출증장적추세,단증폭병불현저;골격기섬유원형화、핵중심화병변현저감소;비장백기총단백함량、M HCⅡ단백표체현저증가,이 Ub、Atrogin‐1급MuRF‐1적단백표체균현저하강。Ala조여 NC조소서상비각지표차이균무통계학의의。결론:량안산능구삭약노년전기소서골격기위축,기궤제가능여량안산대범소‐단백매체계통적억제유관。
Objective :To investigate the effect of leucine supplementation on muscle atrophy in‐duced by ageing and preliminarily analyzes the possible mechanism .Methods :Thirteen‐month‐old male ICR mice were randomly divided into dietary leucine supplementation (Leu) ,alanine supplementation (Ala) and normal control group (NC) by body weight .Mice in leucine (Leu) and alanine (Ala ) supplementation group were treated with normal chow diet supplemented with 5% leucine and 3 .4% alanine respectively for 8 weeks ,while normal control group were fed with normal diet .Seventeen hours of fasting after the last feeding ,mice were sacrificed . The blood glucose was determined with a portable blood glucose meter .The level of BUN was detected by using spectrophotometry .The profile of plasma free amino acids was detected with an amino acids analyzer .The serum insulin and IGF‐1 concentration were determined by ELISA .The skeletal muscle morphology was observed by using hematoxylin and eosin stai‐ning .The protein expression of Ub ,Atrogin‐1 ,MuRF‐1 as well as MHC Ⅱ was detected by the method of Western blotting after BCA protein assay .Results :Compared with both NC and Ala group ,the results showed that ,leucine supplementation (Leu) did not change the level of body weight ,food intake ,blood glucose ,serum insulin and IGF‐1 ,while the level of BUN was significantly elevated ;The content of plasma leucine was increased ,content of alanine ,glutamic acid and glycine were all depressed significantly .Although the wet ratio of wet white gastroc‐nemius muscle to body weight ,cross‐sectional area and diameter of fibers were not influenced significantly by leucine supplementation ,still showed a tendency to increase .The incidence of rounded and central nucleus fibers was reduced .Moreover ,total protein content ,the protein ex‐pression of MHCⅡ were both elevated ,while the expression of Ub ,Atrogin‐1 and MuRF‐1 in white gastrocnemius muscle were significantly depressed .There weren’t statistically significant differences of all parameters between mice in NC and Ala group .Conclusion :Leucine supple‐mentation significantly attenuates skeletal muscle atrophy in pre‐senile mice ,which may be cor‐related with inhibiting the activity of ubiquitin‐proteasome system .