Siegel A J, Silverman L M, Evans W J
JAMA. 1983 Nov 25;250(20):2835-7.
Mean serum creatine kinase MB isoenzyme (CK-MB) activity in 108 trained marathon runners after competition was 98 +/- 66 (SD) units/L measured by a quantitative electrophoretic technique (normal, less than 5 units/L), or 7.9% of total CK activity. These levels in asymptomatic runners were comparable with peak serum values reported in patients during acute myocardial infarction. Elevated serum levels of CK-MB in runners can arise from skeletal muscle through exertional rhabdomyolysis, from silent injury to myocardium, or from a combined tissue source. To investigate this directly, we analyzed skeletal muscle obtained by needle biopsy for CK isoenzymes from 25 trained male marathon runners and ten sedentary male subjects. The MB isoenzyme accounted for 8.9% +/- 1.3% (SD) of total CK activity per gram of total protein in the skeletal muscle of runners and 3.3% +/- 0.7% (SD) in control tissue, which was significant. Total CK activity was not statistically different between the two groups. Similar relative concentrations of CK-MB in skeletal muscle (8.9%) and serum after competition (7.9%) strongly suggest that elevated serum CK-MB activity in asymptomatic runners arises from a noncardiac or skeletal muscle source.
采用定量电泳技术测定，108名经过训练的马拉松运动员赛后血清肌酸激酶MB同工酶（CK-MB）的平均活性为98±66（标准差）单位/升（正常范围为低于5单位/升），占总CK活性的7.9%。这些无症状运动员的CK-MB水平与急性心肌梗死患者报告的血清峰值相当。跑步者血清CK-MB水平升高可能源于运动性横纹肌溶解导致的骨骼肌损伤、心肌的隐匿性损伤或组织混合来源。为了直接对此进行研究，我们对25名经过训练的男性马拉松运动员和10名久坐的男性受试者进行了针吸活检获取骨骼肌，并分析其CK同工酶。在跑步者的骨骼肌中，每克总蛋白中MB同工酶占总CK活性的8.9%±1.3%（标准差），在对照组织中为3.3%±0.7%（标准差），差异具有统计学意义。两组之间的总CK活性无统计学差异。骨骼肌中CK-MB的相对浓度（8.9%）与赛后血清中CK-MB的相对浓度（7.9%）相似，这有力地表明无症状跑步者血清CK-MB活性升高源于非心脏或骨骼肌来源。
