Votion D-M, Fraipont A, Goachet A G, Robert C, van Erck E, Amory H, Ceusters J, de la Rebière de Pouyade G, Franck T, Mouithys-Mickalad A, Niesten A, Serteyn D
Equine European Centre of Mont-le-Soie, Vielsalm, Belgium.
Equine Vet J Suppl. 2010 Nov(38):268-74. doi: 10.1111/j.2042-3306.2010.00271.x.
Limited information exists about the muscle mitochondrial respiratory function changes that occur in horses during an endurance season.
To determine effects of training and racing on muscle oxidative phosphorylation (OXPHOS) and electron transport system (ETS) capacities in horses with high resolution respirometry (HRR).
Mitochondrial respiration was measured in microbiopsies taken from the triceps brachii (tb) and gluteus medius (gm) muscles in 8 endurance horses (7 purebred Arabians and 1 crossbred Arabian) before training (T0), after two 10 week training periods (T1, T2) and after 2 CEI** endurance races (R1, R2). Muscle OXPHOS capacity was determined using 2 titration protocols without (SUIT 1) or with pyruvate (SUIT 2) as substrate. Electrons enter at the level of Complex I, Complex II or both complexes simultaneously (Complexes I+II). Muscle ETS capacity was obtained by uncoupling Complexes I+II sustained respiration.
T1 improved OXPHOS and ETS capacities in the tb as demonstrated by the significant increase of oxygen fluxes vs. T0 (Complex I: +67%; ETS: +37%). Training improved only OXPHOS in the gm (Complex I: +34%). Among horses that completed the race, a significant decrease in OXPHOS (Complex I: ∼ -35%) and ETS (-22%) capacities was found in the tb with SUIT 2 indicating a reduced aerobic glycolysis. Significant correlations between CK activities and changes in OXPHOS were found suggesting a relationship between exercise-induced muscle damage and depression of mitochondrial respiration.
For the first time, OXPHOS and ETS capacities in equine muscle at different steps of an endurance season have been determined by HRR. Significant alterations in mitochondrial respiratory function in response to endurance training and endurance racing have been observed although these changes appeared to be muscle group specific.
关于耐力赛季期间马匹肌肉线粒体呼吸功能变化的信息有限。
运用高分辨率呼吸测定法（HRR）确定训练和比赛对马匹肌肉氧化磷酸化（OXPHOS）及电子传递系统（ETS）能力的影响。
对8匹耐力马（7匹纯种阿拉伯马和1匹杂交阿拉伯马）在训练前（T0）、两个为期10周的训练期后（T1、T2）以及2场耐力赛（R1、R2）后，从肱三头肌（tb）和臀中肌（gm）采集的肌肉活检样本进行线粒体呼吸测定。使用两种滴定方案测定肌肉OXPHOS能力，一种方案不添加底物（SUIT 1），另一种方案以丙酮酸为底物（SUIT 2）。电子分别在复合体I、复合体II水平进入，或同时在两个复合体水平进入（复合体I+II）。通过使复合体I+II持续呼吸解偶联来获得肌肉ETS能力。
与T0相比，T1时tb的OXPHOS和ETS能力提高，表现为氧通量显著增加（复合体I：增加67%；ETS：增加37%）。训练仅使gm的OXPHOS能力提高（复合体I：增加34%）。在完成比赛的马匹中，采用SUIT 2方案时，tb的OXPHOS能力（复合体I：约降低35%）和ETS能力（降低22%）显著下降，表明有氧糖酵解减少。发现CK活性与OXPHOS变化之间存在显著相关性，提示运动诱导的肌肉损伤与线粒体呼吸抑制之间存在关联。
首次通过HRR测定了耐力赛季不同阶段马肌肉的OXPHOS和ETS能力。观察到耐力训练和耐力赛会引起线粒体呼吸功能显著改变，尽管这些变化似乎具有肌肉群特异性。
