Effects of Magnesium Sulfate on Dynamic Changes in Blood Glucose Levels and Glucose Transporter-3 Expression in the Striatum during Short-term Forced Swimming in Gerbi

[[abstract]]In a previous study, we reported that when gerbils were subjected to a period of forced swimming, glucose levels and magnesium levels in the plasma became elevated. In addition, a pretreatment with magnesium sulfate increased the expression of glucose transporter-3 (GLUT-3) in the cortex. The goal of the present study was to evaluate dynamic changes in blood glucose, lactate and magnesium levels in gerbils that had been subjected to short-term forced swimming using an auto-blood-sampling system. A second goal was to investigation the effects of forced swimming and magnesium sulfate on GLUT-3 expression, glucose and magnesium levels in the striatum, which is involved in energy delivery and motor function. Data collection involved the use of a microdialysis analyzer, a flame atomic absorption spectrometer and western blotting assays to detect glucose, lactate, magnesium and GLUT-3 levels, respectively. Gerbils were subjected to a blood sampling assay and pretreated with saline (n=6) or magnesium sulfate (n=6, 90 mg·kg-1, ip) 30 min before the period of forced swimming. Whole blood glucose, lactate, and magnesium levels increased to 175% and 235%, 305% and 190%, and 102% and 128% of basal levels during swimming in both the control and magnesium sulfate-treated groups (p<0.05). The glucose and magnesium levels during swimming were 60% and 26% greater in the magnesium sulfate-treated group (p<0.05), respectively, whereas the lactate levels were attenuated at 115% (p