Kluge H H, Kluge W H, Hartmann W
Department of Neurochemistry, Clinic of Neurology, Friedrich Schiller-University, Jena, Germany.
Clin Chim Acta. 1999 Apr;282(1-2):135-45. doi: 10.1016/s0009-8981(99)00021-2.
An inhibitor-free assay for the simultaneous determination of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in the cerebrospinal fluid (CSF) is described. It is based on our finding that the individual activity ratios of BChE on both its substrates acetylthiocholine (ACh) and butyrylthiocholine (BCh) in the CSF and in the parallel serum are identical under conditions of at least 5 mmol/l substrate concentration (Q(BChE)SE = Q(BChe)CSF). Considering that AChE only reacts with ACh as substrate and occurs with negligible activities in the serum, the measured individual activity ratio of BChE in the serum (Q(BChE)SE) and the total hydrolysis rate of ACh and BCh in the CSF do allow a precise calculation of the AChE activity in the cerebrospinal fluid. The derivation of the corresponding formula is demonstrated in detail. The inhibitor-free assay was compared with procedures using cholinesterase inhibitors (BW284c51 for AChE and/or iso-OMPA for BChE). Achieving widely identical results in particular between the procedure using the AChE inhibitor and the inhibitor-free test, the latter has decisive advantages: (1) it avoids the use of highly toxic inhibitors, (2) it minimizes the test volume needed, (3) it characterizes additionally the status of the blood-CSF barrier by means of the BChE activity ratio in the CSF and in the parallel serum.
本文描述了一种用于同时测定脑脊液（CSF）中乙酰胆碱酯酶（AChE）和丁酰胆碱酯酶（BChE）的无抑制剂检测方法。该方法基于我们的发现：在底物浓度至少为5 mmol/l的条件下，脑脊液和平行血清中BChE对其底物乙酰硫代胆碱（ACh）和丁酰硫代胆碱（BCh）的个体活性比率相同（Q(BChE)SE = Q(BChe)CSF）。鉴于AChE仅以ACh作为底物发生反应，且在血清中的活性可忽略不计，血清中BChE的个体活性比率（Q(BChE)SE）以及脑脊液中ACh和BCh的总水解速率确实能够精确计算脑脊液中的AChE活性。文中详细展示了相应公式的推导过程。将该无抑制剂检测方法与使用胆碱酯酶抑制剂（用于AChE的BW284c51和/或用于BChE的异氟磷）的检测方法进行了比较。特别是在使用AChE抑制剂的检测方法和无抑制剂检测方法之间取得了广泛相同的结果，后者具有决定性优势：（1）避免使用剧毒抑制剂；（2）将所需检测体积降至最低；（3）通过脑脊液和平行血清中BChE的活性比率额外表征血脑屏障的状态。
