| （1.洛阳师范学院 体育学院，河南 洛阳 471022；2.温州医学院，浙江 温州 325035；3.北京体育大学，北京 100084） 摘 要：通过给SD大鼠注射AMPK激动剂AICAR，提高大鼠骨骼肌中AMPK的活性，探讨AMPK活性变化对骨骼肌蛋白质降解的作用。采用同位素技术测定腓肠肌中AMPK活性的变化；采用实时荧光定量PCR技术，测定腓肠肌中MuRF1、MAFbx基因表达量的变化。结果显示AICAR注射后1、2、7 h，AMPK活性与对照组相比升高，差异有显著性或非常显著性意义(P<0.05或P<0.01)；AICAR注射后7 h，AMPK活性开始下降。AICAR注射后1、2 h，MAFbx mRNA、MuRF1 mRNA表达量与对照组相比升高，分别升高2.45、2.23倍和2.67、2.30倍，差异有非常显著性意义(P<0.01)；AICAR注射后7 h，MuRF1 mRNA表达量升高了2.01倍，差异有显著性意义(P<0.05)；而MAFbx mRNA表达有升高趋势，但差异没有显著性。3-MH质量摩尔浓度各组间差异没有显著性意义。结果说明：(1)大鼠一次性注射AICAR后，能显著提高骨骼肌中AMPK的活性，AMPK活性的升高能促进MAFbx mRNA和MuRF1 mRNA的表达，促进骨骼肌蛋白质的降解；(2)推测在反映骨骼肌蛋白质降解方面，MAFbx mRNA和MuRF1 mRNA比3-MH的敏感度要高。 |
MA Yan-chao1，ZHU Rong2，XU Shou-sheng3，WANG Rui-yuan3
| （1.School of Physical Education，Luoyang Normal University，Luoyang 471022，China；2.Wenzhou Medical College，Wenzhou 325035，China；3.Beijing Sport University，Beijing 100084，China） Abstract: By injecting AICAR, an AMPK excitant, into SD rats to boost the activity of AMPK in the skeletal mus-cles of the rats, the authors probed into the effects of AMPK activity changes on the degradation of proteins in skeletal muscles. The authors measured the changes of the AMPK activity in gastrocnemius by using isotope tech-nology, and measured the changes of the level of expression of genes MuRF1 and MAFbx in gastrocnemius by us-ing real time fluorescence quantification PCR technology. Results: 1 h, 2 h and 7 h after AICAR was injected, the AMPK activity increased as compared with the control group, and the differences were significant or very signifi-cant (P<0.05 or P<0.01), and 7 h after AICAR was injected, the AMPK activity started to decrease; 1 h and 2 h after AICAR was injected, the levels of expression of MAFbx mRNA and MuRF1 mRNA increased respectively by 2.45 times, 2.23 times and 2.67 times, 2.30 times as compared with the control group, and the differences were very sig-nificant (P<0.01); 7 h after AICAR was injected, the level of expression of MuRF1 mRNA increased by 2.01 times, and the difference was significant (P<0.05), while the level of expression of MAFbx mRNA increased somewhat, but the difference was not significant; there was no significant difference in the 3-MH content between various groups. The results indicated the followings: 1) after AICAR was injected into the rats once, it can significantly in-crease the activity of AMPK in skeletal muscles, while the increase of the AMPK activity can boost the expression of MAFbx mRNA and MuRF1 mRNA and the degradation of proteins in skeletal muscles; 2) the authors conjec-tured that in terms of reflecting the degradation of proteins in skeletal muscles, MAFbx mRNA and MuRF1 mRNA are more sensitive than 3-MH. |
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