中文摘要：

目的观察肺气肿对大鼠外周骨骼肌生物力学、病理形态学及氧化代谢功能的影响。方法采用随机数字表法将20只SD大鼠分为肺气肿组及对照组。通过向气管内滴注猪胰弹性蛋白酶将肺气肿组大鼠制作肺气肿动物模型，对照组大鼠则于相同时间点向气管内滴注生理盐水。于滴药后第20周时行大鼠原位腓肠肌生物力学测定，并检测肌纤维组分构成、毛细血管密度、肌细胞内脂褐素包涵体含量（LI／F）、一氧化氮合酶（NOS）在腓肠肌中的表达及肌肉组织匀浆中氧化代谢酶活性变化。结果肺气肿组大鼠腓肠肌抗疲劳耐力降低，肌力半数恢复时间[（145．0±55．4）s]较对照组[（55．2±29．3）s]延长（P〈0．05），I型肌纤维比例[（16．0±5．0）％]较对照组[（30．7±4．1）％]降低（P〈0．05），IIb／x型肌纤维比例[（27．3±4．8）％]较对照组[（11．0±3．2）％]增高（P〈0．05）；毛细血管密度[（513．9±71．1）n／mm2]较对照组[（578．6±59．9）n／mm2]降低（P〈0．05）；腓肠肌脂褐素包涵体含量（3．3±0．5）较对照组（1．7±0．4）增高（P〈0．05）；腓肠肌组织中内皮细胞型NOS（eNOS）表达（1．9±0．5）较对照组（3．4±0．6）降低（P〈0．05），神经元型NOS（nNOS）表达与对照组间差异无统计学意义（P〉0．05），诱导型NOS（iNOS）在2组大鼠腓肠肌中均未见发现。结论肺气肿可导致大鼠外周骨骼肌生物力学、病理形态学及氧化代谢功能发生异常改变。

英文摘要：

Objective To study the effects of emphysema on peripheral skeletal muscle biomechanics, pathomorphology and oxidative metabolism in rats. Methods Twenty Sprague-Dawley rats were used and randomized equally into a control group and an emphysema group. A dose of 40 U/100 g body weight of porcine pancreatic elastase was instilled into the trachea of the animals of the emphysema group to model emphysema, while the same volume of saline was instilled into those of the control group. Twenty weeks after instillation, in situ mechanical properties of gastrocnemius were evaluated. Gastrocnemius fiber type composition and capillary density （CD） were assessed by using ATPase staining. Lipofuscin accumulation （LI/F） was determined with the ferric-ferricyanide reduction test technique. Immunohistochemistry was used for the detection of nitric oxide synthases （NOS） in gastrocnemius. The muscle biopsy homogenate was used to measure the activity of superoxide dismutase （SOD）, catalase （CAT） , NOS, total antioxidant capacity （T-AOC） and the content of nitric oxide （NO）. Results Emphysema increased fatigability and decreased the recovery rate of gastroenemius muscle [ （ 145. 0 ±55. 4） s vs （55. 2 ± 29.3）s,P 〈 0. 05 ]. Compared to control, the gastroenemius muscle in rats with emphysema had a lower CD [（513.9 ±71. 1）n/ram2 vs （578. 6 ± 59. 9）n/mm2,P 〈 0. 05] and a decreased proportion of type I fibers [（16.0±5.0）% vs （30.7 ±4.1）% ,P〈0.05], with a reciprocal increase in type II b/x fibers [（27.3 ±4.8）% vs （11.0±3.2）%,P〈0.05]. LI/F was higher （3.3 ±0.5 vs 1.7 ±0.4,P〈0.05） and the activity of SOD, CAT and T-AOC was increased in emphysema group. Compared with control, rats with emphysema demonstrated a lower expression of endothelial NOS （eNOS） （ 1.9 ± 0.5 vs 3.4 ± 0.6, P 〈 0.05 ） , and an equivalent expression of neuronal NOS （nNOS）（4.7 ±1.0 vs5.1 ±0.8, P〉0.05）in thegastrocnemius muscle. The inducible NOS （iNOS） was not foun