Influence of activation frequency on cellular signalling pathways during fatiguing contractions in rat skeletal muscle.
Influence of activation frequency on cellular signalling pathways during fatiguing contractions in rat skeletal muscle.
复制标题
大鼠骨骼肌疲劳收缩过程中激活频率对细胞信号通路的影响。
DOI：
10.1113/expphysiol.2006.034249
复制
发表时间：
2006
影响因子：
2.7
通讯作者：
Lovering,RM
中科院分区：
文献类型：
--
作者：
Russ,DavidW;Lovering,RM
Activation frequency as a regulator of physiological responses in skeletal muscle, independent of contractile force, has received little attention. Here, the length–tension and force–frequency relationships were employed to keep active contractile force equal, despite a twofold difference in stimulation frequency (15versus30 Hz). Rat tibialis anterior muscles were testedin situusing 15 Hz stimulation at optimal length (15 Hz) and 30 Hz stimulation at shortened and lengthened positions (30 Hzsuband 30 Hzsupra). Muscles were subjected to 1, 15, 30 and 80 Hz stimulation trains before and after 2 min of fatiguing stimulation. The principal findings were that the two 30 Hz protocols produced greater 38 kDa MAPK (p38) phosphorylation than the 15 Hz protocol (1.4‐ to 1.5‐foldversus1.1‐fold), as well as greater fatigue (65–78versus43% decline in contraction force). In contrast, c‐jun amino terminal kinase (JNK) phosphorylation appeared most responsive to total (active plus passive) tension such that the changes followed the pattern: 30 Hzsupra> 15 Hz > 30 Hzsub, while 44 and 42 kDa extracellular regulated kinase (ERK1/2) phosphorylation was not significantly increased in response to any of the protocols studied. Neither glycogen depletion nor myofibre damage accounted for any of the findings, but a decline in muscle excitation (m‐wave) may have contributed to the greater fatigue seen at higher frequencies. These data suggest that neuromuscular activation frequency can influence certain signalling pathways in skeletal muscle, independent of force production.
