Effects of Ca, Mg, and EDTA on creatine kinase activity in cerebrospinal fluid.
Effects of Ca, Mg, and EDTA on creatine kinase activity in cerebrospinal fluid.
复制标题
Ca、Mg 和 EDTA 对脑脊液中肌酸激酶活性的影响。
作者：
Petter Urdal;Johan H. Strgmme
为了准确估计脑脊液中肌酸激酶（CK）活性，样品分数比血清中使用的分数增加约10倍。这增加了干扰物质的浓度，Ca尤其重要。因此，检查了Ca、Mg和EDTA之间的关系。酶活性在每升3 mmol EDTA存在下，每升15 mmol Mg时最大，否则根据（斯堪的纳维亚）推荐的血清CK活性测定条件。这些修饰使CK-MM和CK-BB的CK活性分别增加了35%和60%。钙抑制的抵消是这种增加的主要原因。我们描述了一个实用和敏感的方法来确定CK在脑脊液中。
For one to obtain a precise estimate of creatine kinase (CK) activity in cerebrospinal fluid, the sample fraction is increased by about 10-fold over that used for serum. This increases the concentration of interfering substances, Ca being especially important. Therefore, the relationship between Ca, Mg, and EDTA was examined. Enzyme activity was maximal with 15 mmol of Mg per liter in the presence of 3 mmol of EDTA per liter, otherwise according to the (Scandinavian) recommended conditions for determination of CK activity in serum. These modifications increased the activity of CK by 35% for CK-MM and by 60% for CK-BB. Counteraction of Ca-induced inhibition was the main reason to this increase. We describe a practical and sensitive method for determining CK in cerebrospinal fluid.