Department of Respiratory Medicine, Beijing Institute of Respiratory Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China.
Chin Med J (Engl). 2010 Jan 5;123(1):40-4.
Peripheral skeletal muscle dysfunction in patients with chronic obstructive pulmonary disease (COPD) may be due to the disease per se or as a result of concomitant confounding factors. Although the mechanistic basis for this functional impairment is uncertain, oxidative stress may play a role. The purpose of this study was to investigate whether local oxidative stress is associated with the reduced peripheral skeletal muscle performance in rats with emphysema.
In situ mechanical properties of gastrocnemius were measured in Sprague-Dawley rats 5 months after intratracheal instillation of either elastase (EMP, n = 10) or normal saline (CON, n = 10). Lipofuscin inclusions, myocyte apoptosis and antioxidant enzyme activities were examined in the gastrocnemius muscle.
Lipofuscin inclusions were significantly higher in the gastrocnemius muscle of EMP compared with CON (3.2 + or - 0.4 vs. 1.7 + or - 0.4, P < 0.01). The activities of antioxidant enzymes were significantly increased in muscle homogenates of EMP as compared to CON. No significant differences were found in myocyte apoptosis between EMP and CON (1.2 + or - 0.9 vs. 1.0 + or - 0.8, P > 0.05). EMP decreased the fatigue endurance of gastrocnemius muscle (half-time to fatigue recovery: (150.0 + or - 55.4) seconds vs. (55.2 + or - 29.3) seconds, P < 0.01) and had no effect on maximal tetanic force ((467.4 + or - 36.6) g vs. (493.2 + or - 30.5) g, P > 0.05). A significantly positive correlation was found between the level of lipofuscin inclusions and the half-time to fatigue recovery of gastrocnemius muscle in EMP (r = 0.664, P < 0.05).
Local oxidative stress may have important functional consequences for peripheral skeletal muscle in rats with EMP.
慢性阻塞性肺疾病（COPD）患者外周骨骼肌功能障碍可能是由于疾病本身或伴随的混杂因素所致。尽管这种功能障碍的机制基础尚不确定，但氧化应激可能起作用。本研究旨在探讨肺气肿大鼠外周骨骼肌性能下降是否与局部氧化应激有关。
5 个月后，通过气管内滴注弹性蛋白酶（EMP，n=10）或生理盐水（CON，n=10）在 Sprague-Dawley 大鼠中测量比目鱼肌的原位机械性能。检查比目鱼肌中的脂褐素包涵体、肌细胞凋亡和抗氧化酶活性。
EMP 大鼠比目鱼肌中的脂褐素包涵体明显高于 CON（3.2+/-0.4 对 1.7+/-0.4，P<0.01）。与 CON 相比，EMP 肌肉匀浆中的抗氧化酶活性显著增加。EMP 和 CON 之间的肌细胞凋亡无显著差异（1.2+/-0.9 对 1.0+/-0.8，P>0.05）。EMP 降低了比目鱼肌的疲劳耐力（疲劳恢复半时间：（150.0+/-55.4）秒对（55.2+/-29.3）秒，P<0.01），对最大强直力无影响（（467.4+/-36.6）g 对（493.2+/-30.5）g，P>0.05）。EMP 中脂褐素包涵体水平与比目鱼肌疲劳恢复半时间之间存在显著正相关（r=0.664，P<0.05）。
局部氧化应激可能对 EMP 大鼠外周骨骼肌有重要的功能影响。
