Urdal P, Strømme J H
Clin Chem. 1979 Jan;25(1):147-50.
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.
为了精确估算脑脊液中的肌酸激酶（CK）活性，样本量需比测定血清时增加约10倍。这会增加干扰物质的浓度，其中钙尤为重要。因此，研究了钙、镁和乙二胺四乙酸（EDTA）之间的关系。在每升含有3 mmol EDTA的情况下，每升15 mmol镁时酶活性最高，其他条件则按照（斯堪的纳维亚）推荐的血清CK活性测定条件。这些改进使CK-MM的活性提高了35%，CK-BB的活性提高了60%。钙诱导抑制作用的抵消是活性增加的主要原因。我们描述了一种实用且灵敏的脑脊液CK测定方法。
