Abstract: Objective: To analyze and evaluate the impact of the changes in the membrane-related energetic metabolism on the cellular lactate production of different muscular cells in septic rats as compared to that of the normal ones. Methods: Using a rat sepsis model, we established the in vitro muscle incubation system with sufficient oxygen supply as well as the NADH fluorometry method for the detection of trace amount of lactate in the samples. By using the specific ATPase inhibitor ouabain, the activity of Na⁺ pump was inhibited to various degress and the lactate production of the muscle cells was measured accordingly.Results: （1） the lactate production was significantly inhibited by ouabain in muscle cells both in normal and septic rats; （2） The inhibitory effects of ouabain on aerobic glycolysis in the extensor digitorium longus （EDL） muscles were more obvious and sensitive than those in the soleus muscles. Conclusion: In normal and septic states, the activity of the Na⁺ pump may be stimulated by several factors in relationship with cellular functional activities, which in turn play important roles in the increment of lactate production in muscle cells.