Sewell D A, Harris R C, Marlin D J
Department of Physiology, Animal Health Trust, Newmarket, Suffolk, U.K.
Comp Biochem Physiol Comp Physiol. 1994 May;108(1):87-96. doi: 10.1016/0300-9629(94)90059-0.
Skeletal muscle samples were obtained by needle biopsy from two depths of the m. gluteus medius of 50, young race-trained thoroughbred racehorses. Histochemical and biochemical characteristics of the muscle samples were analysed. Fibres were classified as type I, type IIa or type IIb on the basis of the pH dependent lability of the myosin ATPase reaction. The activities of citrate synthase (CS) and glycogen phosphorylase (Phos) were determined. Muscle fibre composition varied markedly between deep and superficial muscle samples and this was reflected in differences in the activities of citrate synthase (CS) and phosphorylase (Phos). CS activity was greater in samples taken from a depth of 90 mm (deep) than those taken from a depth of 40 mm (superficial: 122 +/- 19 compared with 88 +/- 16 mumol/g dry muscle/min at 25 degrees C). Phos activity was greater in superficial samples (137 +/- 20) compared with deep samples (117 +/- 21). Regression analysis was used to estimate the enzyme activities in the different fibre types. No significant correlations were observed between histochemical and biochemical measures and subsequent racing performance.
从50匹年轻的、经过赛事训练的纯种赛马的臀中肌两个深度处通过针刺活检获取骨骼肌样本。对肌肉样本的组织化学和生化特性进行了分析。根据肌球蛋白ATP酶反应的pH依赖性不稳定性，将纤维分为I型、IIa型或IIb型。测定了柠檬酸合酶（CS）和糖原磷酸化酶（Phos）的活性。深层和浅层肌肉样本之间的肌纤维组成差异显著，这反映在柠檬酸合酶（CS）和磷酸化酶（Phos）活性的差异上。在25℃时，取自90毫米深度（深层）的样本中CS活性高于取自40毫米深度（浅层）的样本（分别为122±19和88±16微摩尔/克干肌肉/分钟）。浅层样本中的Phos活性（137±20）高于深层样本（117±21）。采用回归分析来估计不同纤维类型中的酶活性。在组织化学和生化指标与随后的比赛成绩之间未观察到显著相关性。
