Effectiveness of Amino Acids in Alleviating Muscle Damage and Fatigue Resulting from Hyper-running

Abstract

Non-athletes such as weekend sports enthusiasts suffer from muscle damage and fatigue after exercise more so than trained athletes after a bout of sport activity. We reported a novel animal model for trained and untrained athletes, utilizing the hyper-running behavior which was elicited by stimulating the ventromedial nucleus of the hypothalamus (VMH) with bicuculline methiodide (BMI). PURPOSE: To determine the effect of oral administration of an amino acid mixture in alleviating exercise-induced muscle damage and post-exercise fatigue. METHODS: Male 7-week-old Wistar rats were acclimatized for about one week prior to the surgery. Rats were housed individually in a stainless steel cage without a running wheel to prevent them from performing undue running exercise. Upon surgery, a stainless steel guide cannula was stereotaxically inserted unilaterally to the point 1mm above the VMH. One week later, the hyper-running was induced by injecting 0.25 nmol of BMI in 0.5 JJ.1 of the water-absorbent polymer gel into the VMH through the injection cannula which was inserted into the guide cannula. The mixture of amino acids (Ohtani et al., Biosci. Biotechnol. Biochem. 2001 65:348–355.) was orally administrated 30 minutes prior to and immediately after the running. Hyper-running performance was evaluated by the total distance, the maximum speed, and the duration of running. Plasma creatine phosphokinase (CPK), blood lactic acid, and plasma free amino acids were measured at the resting, immediately after the running, and thereafter. Food consumption was monitored throughout the experiment. RESULTS: Between the control group (C) and the amino acid treatment (AA), no significant difference was observed in the running performance: the total distance ranging around 525 m, the maximum speed around 34 m/min., and the duration around 42 minutes. Plasma CPK was elevated 6-fold and 4.5-fold immediately after the running, and declined to 5-fold and 2-fold two hours later in the C and in the AA, respectively. Plasma CPK returned to the pre-running level in 6 hours. Plasma CPK two hours after the running was significantly reduced in the AA. After the running, lactic acid increased, however, the level was significantly lower in the AA. When the change in plasma concentrations of amino acid-related compounds after the running was compared, ammonia and tyrosine concentrations remained lower, and urea, ornithine, and alanine concentrations remained higher in the AA. Food consumption was significantly decreased in the C. CONCLUSIONS: Oral administration of the amino acid mixture before and after the running reduced the muscle damage and fatigue resulting from hyper-running.