Puleo P R, Guadagno P A, Roberts R, Perryman M B
Department of Medicine, Baylor College of Medicine, Houston, TX 77030.
Clin Chem. 1989 Jul;35(7):1452-5.
The subforms of creatine kinase (CK; EC 2.7.3.2) in plasma have received recent attention as potential markers for the early diagnosis of acute myocardial infarction. Because changes in CK-MM subforms are not specific for myocardial injury, we developed an assay, based on high-voltage electrophoresis, that is sufficiently sensitive to detect the CK-MB subforms at concentrations substantially below the upper limit of normal (14 U/L). The assay can detect 1.25 U of either MB subform per liter with a precision of 0.20 U/L and gives responses that vary linearly with activity concentration from 0.0 through 30.0 U/L, with an identical signal response for both subforms. When both subforms are present in a serum sample, the assay accurately measures both the relative percentage and the absolute quantity of each: assay activity/known activity was 1.03 for each subform at a total MB subform activity of 5.0 U/L (r = 0.98). Assay time is 25 min, and there is no loss of CK during electrophoresis. Thus, this system can be used to rapidly, sensitively, and precisely quantify the two CK-MB subforms at activities well within the normal reference interval.
血浆中肌酸激酶（CK；EC 2.7.3.2）的亚形式作为急性心肌梗死早期诊断的潜在标志物最近受到了关注。由于CK-MM亚形式的变化并非心肌损伤所特有，我们开发了一种基于高压电泳的检测方法，该方法足够灵敏，能够检测浓度远低于正常上限（14 U/L）的CK-MB亚形式。该检测方法每升能检测到1.25 U的任何一种MB亚形式，精密度为0.20 U/L，其响应与活性浓度在0.0至30.0 U/L范围内呈线性变化，两种亚形式的信号响应相同。当血清样品中同时存在两种亚形式时，该检测方法能准确测量每种亚形式的相对百分比和绝对量：在总MB亚形式活性为5.0 U/L时，每种亚形式的检测活性/已知活性为1.03（r = 0.98）。检测时间为25分钟，电泳过程中CK无损失。因此，该系统可用于在正常参考区间内快速、灵敏且精确地定量两种CK-MB亚形式的活性。
