Assenza A, Bergero D, Tarantola M, Piccione G, Caola G
Dipartimento di Morfologia, Biochimica, Fisiologia e Produzioni Animali, Università di Messina, Polo Universitario dell'Annunziata, Messina, Italy.
J Anim Physiol Anim Nutr (Berl). 2004 Apr;88(3-4):172-7. doi: 10.1111/j.1439-0396.2004.00493.x.
During long-distance exercise, branched-chain amino acid (BCAA) catabolism could lead to an increase in the blood tryptophan/BCAA ratio and an early onset of 'central fatigue'. Based on these considerations, we studied the modifications of blood serum BCAA and tryptophan (Try) levels in 30 endurance horses competing in rides varying in distance from 20 to 72 km. From all horses, blood samples were drawn just before and just after the end of the ride. Samples were analysed for their leucine (Leu), valine (Val), isoleucine (Iso) and Try levels. Data were processed by anova, using sampling moment and ride as factors, and by LSD post hoc test. Significant differences were recorded among the different distance rides for Leu, Val, Iso, Try, Try/BCAA ratio; the same trend was recorded between samples taken at the start and the end of the race for Val and Leu. The main effect observed was an increase of BCAA levels for all rides, except the 72-km ride; for Try, a significant increase was present in all races, except the 50-km ride. The Try/BCAA ratio decreased in 20- and 50-km races and increased in the others. These data confirm that long-distance exercise involves a mobilization of BCAA. The utilization of BCAA seems to be important in prolonged exercise: in the 72-km ride, we observed a decrease in BCAA blood serum levels, while a major role of Try was indicated by its increase, resulting in a rise of the Try/BCAA ratio.
在长距离运动过程中，支链氨基酸（BCAA）分解代谢可能导致血液中色氨酸/支链氨基酸比值升高，并引发“中枢性疲劳”提前出现。基于这些考虑因素，我们研究了30匹耐力赛马在20至72公里不同距离赛程中的血清支链氨基酸和色氨酸（Try）水平的变化。在每场比赛开始前和结束后，从所有马匹采集血样。对样本进行亮氨酸（Leu）、缬氨酸（Val）、异亮氨酸（Iso）和色氨酸水平分析。数据采用方差分析进行处理，以采样时间和赛程作为因素，并采用最小显著差法（LSD）进行事后检验。在不同距离赛程的亮氨酸、缬氨酸、异亮氨酸、色氨酸、色氨酸/支链氨基酸比值方面记录到显著差异；在比赛开始和结束时采集的样本中，缬氨酸和亮氨酸呈现相同趋势。观察到的主要效应是，除72公里赛程外，所有赛程的支链氨基酸水平均升高；对于色氨酸，除50公里赛程外，所有比赛中均显著升高。在20公里和50公里赛程中，色氨酸/支链氨基酸比值下降，而在其他赛程中则升高。这些数据证实，长距离运动涉及支链氨基酸的动员。支链氨基酸的利用在长时间运动中似乎很重要：在72公里赛程中，我们观察到血清支链氨基酸水平下降，而色氨酸的增加表明其起主要作用，导致色氨酸/支链氨基酸比值升高。
