Articles : Influence of BCAA Administration on Plasma Content and CNS Fatigue during Exercise in Rats

Journal of Exercise Nutrition & Biochemistry 2005;9(1):65-72.

Abstract

Purpose: The purpose of this study was to investigate the influence of BCAA administration on plasma content and CNS fatigue during exercise in rat. Methods: 21 male SD rats were divided into three groups, control (CON), exercise group with only saline (SAL), and exercise group with BCAA (BCAA), respectively. All rats were trained on a motor driven treadmill. Injected intraperitoneally with 1mL of saline (0.9% NaCl) or BCAA (30 mg dissolved in lmL saline) 5niin before 30min of submaximal exercise at the speed of 20 m/min, 9% incline (N = 14). BCAA composition was 10mg, 10mg and 10mg for leucine, isoleucine and valine. After the submaximal exercise test, blood was collected for the measurement of glucose, lactate, FFA. BCAA, and free tryptophan and brain samples were taken from the rat brain for determination of brain tryptophan, 5-HTP, 5-HT, 5-HIAA concentration by HPLC-ECD. Result: The plasma glucose concentration was significantly lower (p＜.05) in the exercise group (SAL, BCAA) compared with the CON. whereas, the plasma FFA concentration was significantly higher (p＜.05) in the exercise group (SAL, BCAA) compared with the CON. The plasma lactate concentration was significantly higher (p＜.05) in the BCAA compared with the CON, and no significant differences were observed between the SAL group and the BCAA group. The plasma free tryptophan concentration was showed the tendency to increase in the exercise group (SAL, BCAA) compared with the CON. The plasma BCAA concentration was significantly higher (p＜.05) in the BCAA compared with other groups. The free try ptophan/BCAA ratio was significantly lower (p＜.05) in the BCAA compared with the SAL. The brain tryptophan, 5-HTP, 5-HT, and 5-HIAA concentrations were showed the tendency to decrease in the BCAA compared with the SAL. Conclusion: We expected that pre-exercise BCAA administration could decrease brain tryptophan and 5-HT concentrations and could increase exercise performance however, there was a tendency towards a lower brain tryptophan, 5-HTP, 5-HT, and 5-HIAA concentrations. Therefore, It is suppose that additional research on BCAA which could affect exercise performance and the activation of the enzyme which could affect 5-HT synthesis are required.

Key Words: BCAA, CNS fatigue, Exercise, Rats