Effects of exogenous lactate administration on fat metabolism and glycogen synthesis factors in rats

Abstract

Lactate has several beneficial roles as an energy resource and in metabolism. However, studies on the effects of oral administration of lactate on fat metabolism and glycogen synthesis are limited. Therefore, the purpose of the present study was to investigate how oral administration of lactate affects fat metabolism and glycogen synthesis factors at specific times (0, 30, 60, 120 min) after intake. [Methods] Male Sprague Dawley (SD) rats (n = 24) were divided into four groups as follows: the control group (0 min) was sacrificed immediately after oral lactate administration; the test groups were administered lactate (2 g/kg) and sacrificed after 30, 60, and 120 min. Skeletal muscle and liver mRNA expression of GLUT4, FAT/CD36, PDH, CS, PC and GYS2 was assessed using reverse transcription-polymerase chain reaction. [Results] GLUT4 and FAT/CD36 expression was significantly increased in skeletal muscle 120 min after lactate administration. PDH expression in skeletal muscle was altered at 30 and 120 min after lactate consumption, but was not significantly different compared to the control. CS, PC and GYS2 expression in liver was increased 60 min after lactate administration. [Conclusion] Our results indicate that exogenous lactate administration increases GLUT4 and FAT/CD36 expression in the muscle as well as glycogen synthase factors (PC, GYS2) in the liver after 60 min. Therefore, lactate supplementation may increase fat utilization as well as induce positive effects on glycogen synthesis in athletes.

Acute Administration of Exogenous Lactate Increases Carbohydrate Metabolism during Exercise in Mice

“…Nevertheless, the effect of lactate intake on metabolism during exercise has not yet been directly investigated. In the aforementioned study by Kyun et al [ 24 ], it was also confirmed that glycogen synthesis- and fat metabolism-related factors increased over time after lactate administration. This study investigated the metabolic changes in exogenous lactate intake at rest over time; however, it did not determine the effect of lactate on metabolism during exercise.…”

“…Interestingly, we have previously confirmed the potential of lactate as a supplement by examining the effects of lactate intake at rest on metabolism [ 23 , 24 ]. The main aim of the present study was to investigate the effect of lactate intake on metabolism during exercise.…”

“…Moreover, Kyun et al [ 23 ] reported that exogenous lactate administration increased the mRNA and protein levels of protein-synthesis-related factors in the skeletal muscle, suggesting the potential of lactate as a supplement that promotes muscle synthesis. In addition, at rest, exogenous lactate intake increased glycogen synthesis- and fat metabolism-related factors [ 24 ]. These findings suggest the potential of exogenous lactate as a new exercise supplement.…”

The Effects of Exogenous Lactate Administration on the IGF1/Akt/mTOR Pathway in Rat Skeletal Muscle

“…Thirty-two rats were used in the study. They were randomly divided into 4 groups that were sacrificed at 0 min (control group), 30 min, 60 min, or 120 min after lactate administration with an oral sonde (Figure 1) at a concentration of 2 g/kg [22,23]. All rats were fasted for 2 h before lactate administration and were euthanized by vertebral dislocation at the predetermined time points.…”

“…Immediately after sacrifice, 3 mL blood samples were obtained from the arteries, and skeletal muscle tissues (plantaris) were quickly removed, frozen in liquid nitrogen, and stored at −80 • C until analysis. oral sonde (Figure 1) at a concentration of 2 g/kg [22,23]. All rats were fasted for 2 h before lactate administration and were euthanized by vertebral dislocation at the predetermined time points.…”