Papadopoulos S, Jürgens K D, Gros G
Zentrum Physiologie, Medizinische Hochschule, Hannover, Germany.
Pflugers Arch. 1995 Aug;430(4):519-25. doi: 10.1007/BF00373888.
We measured the diffusion coefficient of myoglobin (DMb) inside mammalian skeletal muscle cells with a microinjection technique. A small bolus of horse Mb was injected into a single muscle fibre and the subsequent time-dependent changes of the Mb profiles along the fibre axis were measured with a microscope-photometer. For fibres of the rat soleus muscle at 22 degrees C, a DMb of 1.3.10(-7) cm2/s was found, confirming a result obtained previously by us for rat diaphragm muscle with a photo-oxidation technique. In the extensor digitorum longus muscle of the rat, a higher value of 1.9.10(-7) cm2/s was measured. Auxotonic muscle contractions did not change the apparent DMb. For the temperature range between 22 degrees C and 37 degrees C, a temperature coefficient. Q10, of 1.5 was calculated. The implication of this result for the role of Mb in the facilitation of oxygen transport was examined. Model calculations show that with this relatively low DMb value, the intracellular oxygen supply can be improved only slightly.
我们采用显微注射技术测量了哺乳动物骨骼肌细胞内肌红蛋白的扩散系数（DMb）。将一小团马肌红蛋白注入单根肌纤维，随后用显微镜光度计测量肌红蛋白分布沿纤维轴随时间的变化。对于22℃的大鼠比目鱼肌纤维，测得DMb为1.3×10⁻⁷ cm²/s，证实了我们之前用光氧化技术在大鼠膈肌上得到的结果。在大鼠趾长伸肌中，测得的值更高，为1.9×10⁻⁷ cm²/s。等张收缩并未改变表观DMb。在22℃至37℃的温度范围内，计算出温度系数Q10为1.5。研究了该结果对肌红蛋白在促进氧气运输中作用的影响。模型计算表明，由于该DMb值相对较低，细胞内氧气供应只能得到轻微改善。
