Lactate Administration Stimulates Fat Oxidation and Liver Glycogen Storage in Resting Rats

Background/Aims: Lactate is known as the end-product of glycolysis, and induces peripheral fatigue. However, since last decades there has been demonstrated positive effect of lactate administration. In this study, we investigated effects of lactate ingestion on energy utilization in rats. Methods: 32 Sprague-Dawley rats were divided into control, caffeine (10 mg/kg), lactate (4 g/kg), and caffeine and lactate mixed compound. Results: There was no significant difference in oxygen uptake between groups for 6 hr. However, Lac and Caf+Lac significantly increased fat oxidation. MCT1 mRNA in soleus muscle decreased after 2 hr, and FAT/CD36 mRNA in soleus muscle showed up and down tendency with significant difference within 2 hr. Finally PDK4 mRNA increased by lactate ingestion. Furthermore glycogen level in liver significantly increased after 2 hr ingestion. These results mean that lactate administration stimulates fat oxidation and liver glycogen storage in resting rats. Conclusions: Accordingly, we carefully might suggest that lactate could be an effective supplement for glycogen loading in endurance athletes.