Effect of Magnesium on the Dynamic Changes of Energy Metabolites During Exercise

• Main Authors: Hsuan-Ying Chen, 陳宣穎
• Other Authors: Ming-Fu Wang
• Format: Others
• Language: en_US
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/04632491088269443617

博士 === 靜宜大學 === 食品營養學系 === 102 === Magnesium (Mg) is the second most abundant intracellular cation and it is an important modulator of a number of physiological and biochemical processes especially in Mg-nucleotide complex, regulation of ion transporters, energy metabolism and muscle contraction. Many researches indicated that Mg supplementary could improve exercise performance, but the regulated mechanism is still unclear. The aims of the present study were to explore the effect of Mg on the exercise performance and dynamic changes of energy metabolites. First part of this study was to evaluate the effect of Mg on the exercise performance and the blood energy metabolites changes. All Sprague-Dawley rats were received saline (control group) or Mg (Mg group, MgSO4 90 mg/kg) supplementary via intraperitoneal injection 30 minutes before exercise. In the first experiment, rats were recorded the retention frequency to evaluate the exercise performance at three consequent various speeds (10, 15, and 20 m/min for 30 min, respectively) in the 90 minutes treadmill exercise. In the second experiment, rats were performed at a speed of 20 m/min for 30 minutes, and assessed the effect of Mg on the dynamic changes of the blood glucose and lactate concentrations during exercise. The third experiment was to investigate the effect of Mg on the dynamic changes of energy metabolites in the central and peripheral system simultaneously during exercise. Two microdialysis and an auto-blood sampling techniques were integrated for sampling in an exercising rat. The microdialysates and blood samples were collected every 15 min via brain striatum, muscle biceps femoris, and jugular vein during all experiment period. All samples were detected the glucose and lactate concentrations by a CMA/600 analyzer. Results showed that: (1) compared to the speed at 10 m/min in the control group, the exercise performance scores were significantly lower in the higher speeds at 15 and 20 m/min (P<0.05). However, the exercise performance scores were significantly decreased only at speed of 20 m/min when compare to that of 10 m/min in the Mg group (P<0.05). (2) In addition, glucose concentrations in Mg group were rose immediately after Mg administration and further increased during exercise when compared to the control group (P<0.05). (3) The glucose concentrations in the central and peripheral systems were obviously increased and attenuated the lactate concentrations in the peripheral system in the Mg group (P<0.05). In summary, Mg enhanced exercise performance via improving glucose availability in the central and peripheral system and decreasing lactate accumulation in the muscle.