Effect of high temperature and oxidative stress on mitochondrial function of incubated broiler muscle

Chinese. 【目的】研究高温和氧化应激对体外培养肉鸡骨骼肌线粒体功能的影响，初步探讨高温影响肉鸡肌肉品质的机制。【方法】从16只2周龄AA肉鸡的左右小腿后侧分离腓骨长肌，使用不锈钢支架维持肌肉束的正常长度，在95%O2、5%CO2混合气体饱和条件下，体外孵育2 h。分别测定升高孵育温度或在培养介质中添加邻苯三酚后，肉鸡腓骨长肌线粒体活性氧（ROS）产量、钙泵（Ca. ＋-ATPase）活性和乳酸含量的变化。【结果】升高培养温度显著提高肉鸡骨骼肌线粒体H2O2的产生量（P〈0.0001），导致肌肉脂质过氧化（P＝0.0368），抑制线粒体钙泵活性（P＝0.0001），增加乳酸积聚（P〈0.0001），并影响肌纤维膜的完整性，使肌酸激酶（CK）和乳酸脱氢酶（LDH）的流失量增加（P =0.0009，P =0.0114），而培养介质中添加邻苯三酚对肉鸡腓骨长肌产生相似的影响。【结论】高温影响线粒体功能，增加肌肉乳酸浓度，损伤肌纤维膜完整性，这些影响与高温诱导的氧化应激有关。

English. [ Objective ] The present study was conducted to determine the effects of high temperature and oxidative stress on mitochondrial function of incubated broilers muscle. [Method] The bilateral M. fibularis longus muscle of sixteen broilers were incubated in vitro to evaluate the effect of high incubated temperature and pyrogallol on mitochondrial H202 production and Ca. ＋ -ATPase activity. [ Result ] The higher incubation temperature （44.5 ℃） significantly elevated muscle mitochondrial H2O2 production （24.6%） and significantly inhibited Ca. ＋-ATPase activity （19.6%）, and also resulted in the elevation of the lipid peroxidation and lactate content in incubated muscle. The loss of CK （phosphokinase） and LDH from incubated muscle was significantly elevated by higher temperature, which indicated that the integrity of muscle cell membrane was damaged. Pyrogallol, which can produce superoxide anion radicals by autoxidation, at 0.3 mmol・L. 1 has similar effects on incubated muscle as higher temperature. [ Conclusion ] High temperature effected the function of muscle mitochondria, increased lactate concentration, damaged the integrity of muscle cell membrane. The effects of high temperature were associated with oxidative stress.