Garry D J, Ordway G A, Lorenz J N, Radford N B, Chin E R, Grange R W, Bassel-Duby R, Williams R S
Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas 75235, USA.
Nature. 1998 Oct 29;395(6705):905-8. doi: 10.1038/27681.
Myoglobin, an intracellular haemoprotein expressed in the heart and oxidative skeletal myofibres of vertebrates, binds molecular oxygen and may facilitate oxygen transport from erythrocytes to mitochondria, thereby maintaining cellular respiration during periods of high physiological demand. Here we show, however, that mice without myoglobin, generated by gene-knockout technology, are fertile and exhibit normal exercise capacity and a normal ventilatory response to low oxygen levels (hypoxia). Heart and soleus muscles from these animals are depigmented, but function normally in standard assays of muscle performance in vitro across a range of work conditions and oxygen availability. These data show that myoglobin is not required to meet the metabolic requirements of pregnancy or exercise in a terrestrial mammal, and raise new questions about oxygen transport and metabolic regulation in working muscles.
肌红蛋白是一种在脊椎动物的心脏和氧化性骨骼肌纤维中表达的细胞内血红蛋白，它能结合分子氧，并可能促进氧气从红细胞向线粒体的转运，从而在生理需求旺盛时期维持细胞呼吸。然而，我们在此表明，通过基因敲除技术产生的无肌红蛋白小鼠可育，且具有正常的运动能力以及对低氧水平（缺氧）的正常通气反应。这些动物的心脏和比目鱼肌无色素沉着，但在一系列工作条件和氧供应情况下的体外肌肉性能标准检测中功能正常。这些数据表明，在陆生哺乳动物中，怀孕或运动的代谢需求并不需要肌红蛋白来满足，这也引发了关于工作肌肉中氧气运输和代谢调节的新问题。
