Effects of physical exercise on skeletal muscles of rats with cerebral ischemia

Physical exercise is a known preventive and therapeutic alternative for several cerebrovascular diseases. Therefore, the objective of the present study was to evaluate the motor performance and histomorphometry of the biceps brachii, soleus, and tibialis anterior muscles of rats submitted to a treadmill training program prior to the induction of cerebral ischemia via occlusion of the middle cerebral artery (OMCA). A total of 24 Wistar rats were distributed into four groups: Sham-Sed: sedentary control animals (n=6), who underwent sham surgery (in which OMCA did not occur); Sham+Ex: control animals exercised before the sham surgery (n=6); I-Sed: sedentary animals with cerebral ischemia (n=6); and I+Ex: animals exercised before the induction of ischemia (n=6). The physical exercise consisted of treadmill training for five weeks, 30 min/day (5 days/week), at a speed of 14 m/min. The results showed that the type-I fibers presented greater fiber area in the exercised ischemic group (I+Ex: 2347.96±202.77 µm2) compared to the other groups (Sham-Sed: 1676.46±132.21 µm2; Sham+Ex: 1647.63±191.09 µm2; I+Ex: 1566.93±185.09 µm2; P=0.0002). Our findings suggested that the angiogenesis process may have influenced muscle recovery and reduced muscle atrophy of type-I fibers in the animals that exercised before cerebral ischemia.

运动已被证实可作为多种脑血管疾病的预防性与治疗性备选方案。因此，本研究旨在评估在通过大脑中动脉闭塞（OMCA）诱导脑缺血前，接受跑台训练方案的大鼠的运动功能与肱二头肌（biceps brachii）、比目鱼肌（soleus）、胫骨前肌（tibialis anterior）的组织形态计量学（histomorphometry）特征。本研究共纳入24只Wistar大鼠，随机分为4组：假手术静息组（Sham-Sed，n=6），即仅接受假手术（未实施大脑中动脉闭塞操作）的静息对照大鼠；假手术运动组（Sham+Ex，n=6），即假手术前接受运动干预的对照大鼠；缺血静息组（I-Sed，n=6），即诱导脑缺血后保持静息的大鼠；缺血运动组（I+Ex，n=6），即脑缺血诱导前接受运动干预的大鼠。本次运动干预采用跑台训练方案，每周训练5天，每日30分钟，持续5周，训练速度为14 m/min。结果显示，缺血运动组（I+Ex）的I型肌纤维横截面积为2347.96±202.77 µm²，显著高于其余三组：假手术静息组1676.46±132.21 µm²、假手术运动组1647.63±191.09 µm²、缺血静息组1566.93±185.09 µm²（P=0.0002）。本研究结果表明，脑缺血前接受运动干预的大鼠，其血管生成过程可能参与调控肌肉修复，并缓解了I型肌纤维的萎缩。