Université de Lyon, F-69000, Laboratoire de Physiologie Intégrative, Cellulaire et Moléculaire, CNRS-UMR 5123 Université Lyon 1, Villeurbanne, France.
FEBS Lett. 2011 Jan 3;585(1):173-7. doi: 10.1016/j.febslet.2010.11.032. Epub 2010 Nov 21.
We report the first evidence of a mitochondrial NO synthase (mtNOS) in bird skeletal muscle. In vitro, mtNOS activity stimulated by L-arginine reduced intermyofibrillar mitochondrial oxygen uptake and ATP synthesis rates, stimulated endogenous H(2)O(2) generation, but had no effect on oxidative phosphorylation efficiency. Arginine-induced effects were fully reversed by L-NAME, a known NOS inhibitor. When ducklings were cold exposed for 4 weeks, muscle mitochondria displayed an increased state 3 respiration, a reduced H(2)O(2) generation but no significant alteration in mtNOS activity. We conclude that mtNOS is expressed in avian skeletal muscle.
我们首次在鸟类骨骼肌中发现了线粒体一氧化氮合酶（mtNOS）。体外实验表明，L-精氨酸刺激 mtNOS 活性可降低肌间纤维线粒体的耗氧率和 ATP 合成速率，刺激内源性 H2O2 的产生，但对氧化磷酸化效率没有影响。已知的 NOS 抑制剂 L-NAME 可完全逆转精氨酸诱导的作用。当小鸭暴露于寒冷环境中 4 周时，肌肉线粒体的状态 3 呼吸增加，H2O2 的产生减少，但 mtNOS 活性没有明显变化。我们的结论是，mtNOS 在禽类骨骼肌中表达。
