| （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：为探讨一次大强度耐力运动过程中，AMPK活性变化对骨骼肌蛋白质降解的作用。将36只 SD大鼠进行一次跑台运动，坡度5%，运动强度25 m/min，运动时间60 min。取样为运动前、运动0.5、1 h，运动后1、2、6 h等6个点。使用高效液相色谱法测定AMP、ATP质量摩尔浓度；采用同位素技术测定腓肠肌中AMPK活性的变化；采用荧光定量PCR技术，测定腓肠肌中MuRF1、MAFbx基因表达量的变化。结果发现：(1)运动0.5 h到运动后即刻，AMP质量摩尔浓度及AMP与ATP质量摩尔浓度比值升高(P<0.05)，运动后1、2、6 h组，腓肠肌AMP质量摩尔浓度及AMP、ATP质量摩尔浓度比值与安静组比较差异没有显著性；ATP质量摩尔浓度各组变化不大，差异没有显著性。(2)AMPK活性在运动0.5 h后开始升高，运动后2 h达到最高，运动后6 h开始下降但还高于对照组。(3)与安静组比较，运动0.5 h组、运动1 h组MuRF1 mRNA、MAFbx mRNA表达量差异没有显著性；运动后1 h、2 h组MuRF1 mRNA、MAFbx mRNA表达量与安静组比较升高，差异有非常显著性(P<0.01)，分别升高1.98、3.57和1.95、2.55倍；运动后6 h组MuRF1 mRNA、MAFbx mRNA表达量与安静组比较升高，差异有显著性(P<0.05)。结果说明：一次性大强度耐力运动后1~6 h，骨骼肌蛋白质降解可能增强，其原因可能是AMPK活化，促进MAFbx mRNA、MuRF1 mRNA基因表达，促进骨骼肌蛋白质的降解。 |
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: The authors probed into functions played by changes of AMPK activity in the degradation of skeleton muscle protein during one time high intensity endurance exercising. Method: let 36 SD rats do a one time treadmill exercise at a slope of 5%, an exercise intensity of 25 m/min, and an exercise time of 60min. Sampling times were before exercising, after 0.5h and 1h of exercising, 1 h, 2 h and 6 h after exercising. The authors measured AMP and ATP molalities by using high efficiency liquid chromatography, changes of AMPK activity in gastrocnemius mus-cle by using isotope technology, and changes of MuRF1 and MAFbx gene expressions in gastrocnemius muscle by using fluorescence quantification PCR technology. Results: 1) from the moment after 0.5 h of exercising to the movement immediately after exercising, AMP molality and the ratio of AMP molality to ATP molality increased (P<0.05); there was no significant difference in AMP molality and the ratio of AMP molality to ATP molality in gastrocnemius muscle between 1 h, 2 h and 6h after exercising groups and the calm group; there was no significant change or difference in ATP molality between various groups; 2) AMPK activity started to increase after 1.5 h of exercising, reached its peak at 2 h after exercising, started to lower at 6 h after exercising but was still higher than that of rats in the control group; 3) there was no significant difference in MuRF1 mRNA and MAFbx mRNA ex-pression volumes between after 0.5h and 1h of exercising groups and the calm group; compared with those of rats in the calm group, MuRF1 mRNA and MAFbx mRNA expression volumes of rats in 1h and 2 h after exercising groups increased by 1.98 times, 3.57 times and 1.95 times 2.55 times respectively, and the differences were very significant (P<0.01); compared with those of rats in the calm group, MuRF1 mRNA and MAFbxmRNA expression volumes of rats in the 6h after exercising group increased, and the differences were significant (P<0.05). The results indicate that in 1-6 h after one time high intensity endurance exercising, the degradation of skeletal muscle protein may be intensified, possibly by MAFbx mRNA and MuRF1 mRNA gene expressions promoted by AMPK activation. |
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