α-Lipoic acid (ALA) functions as a cofactor of mitochondrial enzymes, is closely related with mechanism of aerobic energy production. Therefore, ALA is expected to provide to improvement of endurance capacity and recovery of fatigue, but it is not well known that ALA has effect of energy metabolism. In this study, we investigated the promoting effects of ALA on energy metabolism in rats, used exercise time to exhaustion in loading swimming test and energy expenditure before and after exercise as indicators. Male Wistar rats were orally administrated 100mg/kg body weight of ALA for 4 weeks. The effects of ALA on exhaustion time were not observed, while resting metabolic rate was significantly increased by daily administration of ALA. Moreover, ALA increased total energy expenditure of the post-exercise, but the difference was not significant. These results suggest that ALA does not enhance endurance, but promotes activation of energy metabolism.

α-リポ酸はミトコンドリアに存在する酸化系酵素の補酵素であり,有酸素系エネルギー代謝に深く関わっている.それゆえ,α-リポ酸摂取が持久性運動能力向上と疲労回復をもたらすと期待されている.しかしながら,α-リポ酸のエネルギー代謝系に及ぼす影響については,あまり検討されていない.そこで本研究では,ウイスター系雄ラットに100mg/kg体重のα-リポ酸を4週間経口投与し,α-リポ酸がエネルギー代謝に及ぼす影響をラットのスイミング運動持続時間,運動前後のエネルギー消費量を指標として検討した.α-リポ酸投与により,安静時のエネルギー消費量は有意に増加し,運動後のエネルギー消費量も増加する傾向が見られたが,スイミング運動持続時間の延長は確認できなかった.これらの結果から,α-リポ酸は,運動能力の向上には寄与しないが,エネルギー代謝を増加させることが示唆された.