[Isoenzymes of creatine kinase: distribution in the skeletal muscle and in sera of patients with muscular diseases or damages (author's transl)].

In skeletal muscle isoenzymes of CK were determined by immunprecipitation and chromatography. The activity of CK-MB was between 17 and 47 U/g muscle, corresponding to a quota between 2,1 and 4,2% of the total activity. In sera of patients with muscular dystrophy, polymyositis, hypothyroidism, after arterial embolism, epilepsy, hyperventilation, operations and polytrauma with and without injury to the thorax isoenzymes were measure by immune precipitation- and immune inhibition-test. The percentage of CK-MB in all sera was less than 6% of the total CK-activity (range: 0 to 6%). Only patients in the first day after neurosurgical operations showed a quota till to 6.5% CK-MB. In serum of patients after polytrauma without injury to the thorax the percentage of CK-MB ranged from 0-5.7% while after polytrauma with injury to the thorax and a reasonable suspicion of a damage to the myocardium this quota was between 5.1 and 23.6% of the total activity. CK-BB activity was not detectable in any cases. Therefore a disease or damage of the skeletal muscle is more probable, if the percentage of CK-MB in less than 6%, because in sera of patients with myocardial infarction in the first 48 h after beginning of the symptoms this quota of CK-MB in the most cases in more than 6%.