McKenzie E C, Eyrich L V, Payton M E, Valberg S J
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Oregon State University, 227 Magruder Hall, Corvallis, OR 97331, USA.
Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Oregon State University, 227 Magruder Hall, Corvallis, OR 97331, USA.
Vet J. 2016 Oct;216:196-201. doi: 10.1016/j.tvjl.2016.08.011. Epub 2016 Aug 24.
A previous report suggests a substantial incidence of exertional rhabdomyolysis (ER) in Arabian horses performing endurance racing. This study compared formalin histopathology and clinical and metabolic responses to a standardised field exercise test (SET) between Arabians with and without ER. Arabian horses with (n = 10; age 15.4 ± 5.6 years) and without (n = 9; 12.9 ± 6.1 years) prior ER were stall-rested for 24-48 h, after which paired ER and control horses were fitted with a telemetric ECG and performed a 47 min submaximal SET. Plasma glucose, lactate, electrolyte and total protein concentrations and packed cell volume were measured before and immediately after exercise. Blood and percutaneous gluteal muscle samples were also obtained before and 3 h after exercise for measurement of plasma creatine kinase (CK) activity and muscle glycogen concentration, respectively. Histopathologic analysis of formalin-fixed pre-exercise muscle sections was performed. Data were analyzed by ANOVA and non-parametric tests (P <0.05). No horses displayed clinical signs of ER during exercise, and plasma CK increased similarly in ER and control Arabians. Muscle glycogen, heart rate, and remaining plasma variables did not differ between horses with ER and control horses. Horses with ER had more internalised nuclei in mature myofibers, more aggregates of cytoplasmic glycogen and desmin, and higher myopathic scores than control horses. Although many horses with ER had histopathologic evidence of chronic myopathy, muscle glycogen concentrations and metabolic exercise responses were normal. Results did not support a consistent metabolic myopathy or a glycogen storage disorder in Arabians with ER.
之前的一份报告表明，参加耐力赛的阿拉伯马中运动性横纹肌溶解症（ER）的发病率相当高。本研究比较了有ER和无ER的阿拉伯马在接受标准化野外运动测试（SET）时的福尔马林组织病理学以及临床和代谢反应。有ER史（n = 10；年龄15.4±5.6岁）和无ER史（n = 9；12.9±6.1岁）的阿拉伯马被关厩休息24 - 48小时，之后为有ER和对照的配对马匹安装遥测心电图，并进行47分钟的次最大强度SET。在运动前和运动后立即测量血浆葡萄糖、乳酸、电解质和总蛋白浓度以及红细胞压积。还在运动前和运动后3小时采集血液和经皮臀肌样本，分别用于测量血浆肌酸激酶（CK）活性和肌肉糖原浓度。对福尔马林固定的运动前肌肉切片进行组织病理学分析。数据采用方差分析和非参数检验进行分析（P < 0.05）。运动期间没有马匹表现出ER的临床症状，ER组和对照阿拉伯马的血浆CK升高情况相似。有ER的马匹和对照马匹之间的肌肉糖原、心率以及其余血浆变量没有差异。与对照马匹相比，有ER的马匹成熟肌纤维中的内化核更多，细胞质糖原和结蛋白聚集体更多，且肌病评分更高。尽管许多有ER的马匹有慢性肌病的组织病理学证据，但肌肉糖原浓度和运动代谢反应正常。结果不支持有ER的阿拉伯马存在一致的代谢性肌病或糖原贮积症。
