Vanderthommen M, Gilles R, Carlier P, Ciancabilla F, Zahlan O, Sluse F, Crielaard J M
Physical Medicine Department, University Hospital, Liège, Belgium.
Int J Sports Med. 1999 Jul;20(5):279-83. doi: 10.1055/s-2007-971131.
Electrical stimulation (ES) and voluntary contraction (VC) were compared in the quadriceps muscle of ten male volunteers. In both modes, a workload corresponding to 20% of maximal voluntary contraction was applied during 64 isometric contraction (5.5 s)-relaxation (5.5 s) cycles. The protocols were performed in a 1.5 T whole-body magnet. The Pi/PCr ratio and the intracellular pH (pHi) were monitored by 31P NMR spectroscopy during baseline, exercise and recovery periods, in a superficial region of the vastus medialis. During baseline, the Pi/PCr ratio (0.12 vs. 0.10) and the pHi (7.01 vs. 7.00) were comparable in both conditions. During exercise, the Pi/PCr ratio was higher (0.36 vs. 0.14) and the pHi was lower (6.85 vs. 7.07) during ES than during VC. For the same external work production, these results reflect a different metabolic solicitation in the ES quadriceps than in the VC ones.
在十名男性志愿者的股四头肌中对电刺激（ES）和自主收缩（VC）进行了比较。在两种模式下，在64个等长收缩（5.5秒）-放松（5.5秒）周期中施加相当于最大自主收缩20%的工作量。实验方案在1.5T全身磁体中进行。在基线期、运动期和恢复期，通过31P核磁共振波谱法监测股内侧肌浅表区域的磷酸肌酸激酶/磷酸肌酸（Pi/PCr）比值和细胞内pH值（pHi）。在基线期，两种情况下的Pi/PCr比值（0.12对0.10）和pHi（7.01对7.00）相当。在运动期间，与VC相比，ES期间的Pi/PCr比值更高（0.36对0.14），pHi更低（6.85对7.07）。对于相同的外部功输出，这些结果反映了ES股四头肌与VC股四头肌不同的代谢需求。
