【摘要】 目的:研究不同强度运动大鼠腓肠肌AMP、ATP含量及AMPK活性,旨在阐明不同强度运动时AMMP/ATP的比值和AMPK的变化特点及二者的关系。方法:将62只雄性SD大鼠分为4大组:安静对照组、小强度运动组、中强度运动组、大强度运动组,其中运动组又各分为3小组,分别在运动后即刻、1 h和6 h取材。小、中和大强度一次性跑台运动的速度分别为10 m/min、18 m/min、26 m/min,坡度10°,时间60 min。AMP、ATP含量测定采用高效液相色谱法(HPLC),AMPK活性测定采用放射性同位素法。结果:小强度运动后AMPK活性不变,中到大强度运动后即刻分别增加50%(P<0.01)和1.8倍(P<0.01)并持续至1 h,6 h回到安静水平;中到大强度即刻AMP分别增加16%(P<0.05)和62%(P<0.01),AMP/ATP分别升高33%(P<0.05)和89%(P<0.01),均在1 h回到安静水平;不同强度运动后即刻AMPK与AMP/ATP呈显著正相关(r=0.89)。结论:1)AMPK在小强度运动时未激活,中到大强度运动时呈强度依赖性升高;2)运动激活AMPK的机制主要受AMP/ATP比值升高调控,而比值的升高主要依赖于AMP的增加而不是ATP的减少;3)运动后AMPK活性的恢复滞后于AMP/ATP比值的恢复。更多还原

【Abstract】 This paper studies the AMP and ATP contents,and 5’-AMP-activated protein kinase (AMPK)activity in rat’s gastrocnemius by different intensity treadmill exercise in this experi- ment.The change feature of AMP:ATP ratio and AMPK activity for different intensity exer- cise was elucidated,as well as the relationship between AMPK and AMP/ATP.62 rats were randomly divided into four groups,namely rest(n=8),low intensity(L,n=18),moderate intensity(M,n=18),and high intensity(H,n=18).Post three groups were divided into im- mediate post-exercise(0),1 h,6h(n=6,respectively).After adaptable training,rats comple- ted a bout treadmill exercise by low,moderate,and high intensity,respectively,as 10m/min speed,10°slope,and 60 min course.AMP and ATP contents were determined by HPLC. AMPK activity was determined by use of the[γ-32P]ATP as P donor and SAMS peptide as substrate.Comparing with rest,the AMPK activity was not changed in L,but increased 50% (P<0.01)and 1.8 fold(P<0.01) at 0 of M and H exercise,respectively,and then re- trieved to rest level at 6h.;AMP contents were significantly changed at 0 of M and H exercise ( 16%,P<0.05;62%,P<0.01,respectively).The ratio of AMP/ATP was increased at 0 of M and H exercise(33%,P<0.05;89%,P<0.01,respectively).AMPK activity was significant positive correlation to AMP.ATP ratio at 0(r=0.89).Conclusions.a.The AMPK activity was no changed by low exercise intensity,but increased as intensity-dependent by mod- erate and high intensity;b.AMPK activity in exercise period was regulated mainly by AMP: ATP ratio increasing which depended rather AMP increasing than ATP decreasing,c.The re- covery of AMPK activity was slower than AMP/ATP post exercise.更多还原