Essén-Gustavsson B, Ronéus N, Pösö A R
Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
Comp Biochem Physiol B Biochem Mol Biol. 1997 Jul;117(3):431-6. doi: 10.1016/s0305-0491(97)00140-5.
Histochemical and biochemical analyses were performed on muscle biopsies obtained after racing from the gluteus muscle of 18 standardbred trotters. Fibre type composition and enzyme activities varied among the horses. The percentage of type IIB fibres showed a positive correlation to the lactate dehydrogenase activity and a negative correlation to the citrate synthase activity. ATP concentrations in whole muscle after racing showed a negative correlation to both lactate and IMP concentrations. Within individual fibres, ATP concentrations varied markedly, with some type II fibres having values as low as 1-5 mmol/kg d.w. and some fibres having values as high as 40-58 mmol/kg d.w., whereas mean ATP concentration for whole muscle was 18.3 +/- 7.7 mmol/kg d.w. Some fibres with low ATP concentrations revealed high IMP concentrations. Blood samples taken after racing showed high values for lactate, ammonia, and uric acid in plasma. Muscle AMP and ADP concentrations after racing were related to the horses placing in a race, with higher concentrations giving a lower placing. The results of this study show that adenine nucleotide breakdown in muscle is of great importance for energy release during racing, and that ATP and IMP concentrations may very markedly among individual fibres. Thus, metabolite analyses on whole muscle must be evaluated with caution, as this only represents a mean value for metabolic responses in different fibres during racing.
对18匹标准赛马赛后从臀肌获取的肌肉活检样本进行了组织化学和生化分析。不同马匹之间的纤维类型组成和酶活性存在差异。IIB型纤维的百分比与乳酸脱氢酶活性呈正相关，与柠檬酸合酶活性呈负相关。赛后全肌肉中的ATP浓度与乳酸和IMP浓度均呈负相关。在单个纤维内，ATP浓度差异显著，一些II型纤维的值低至1 - 5 mmol/kg干重，而一些纤维的值高达40 - 58 mmol/kg干重，而全肌肉的平均ATP浓度为18.3±7.7 mmol/kg干重。一些ATP浓度低的纤维显示出高IMP浓度。赛后采集的血样显示血浆中乳酸、氨和尿酸的值较高。赛后肌肉中的AMP和ADP浓度与马匹在比赛中的名次有关，浓度越高名次越低。本研究结果表明，肌肉中的腺嘌呤核苷酸分解对于比赛期间的能量释放非常重要，并且ATP和IMP浓度在单个纤维之间可能差异很大。因此，对全肌肉的代谢物分析必须谨慎评估，因为这仅代表比赛期间不同纤维代谢反应的平均值。
