血清对氧磷脂酶活性连续检测方法的建立及临床意义

Determination of paraoxonase activities in serum with continuous-monitoring and its clinical value

目的建立血清中对氧磷脂酶(PON)活性测定的方法,测定正常人和肝硬化患者血清中PON的活性,探讨该酶诊断肝硬化的意义。方法PON活性测定以乙酸苯酯为底物,在PON的作用下水解,生成苯酚,用分光光度计在37℃、270nm处连续监测3min测定苯酚特征性的紫外吸收,计算出酶促反应速度。结果本方法的最适的测定条件为37℃、270nm处连续监测3min,底物浓度为10mmol/L,最适pH值为8.0,激活剂Ca2+浓度为2mmol/L,批内变异系数(CV)可达4.3%,批间CV为5.0%。正常人组血清PON活性为(284.95±83.76)U/ml,参考范围为201.2～368.7U/ml,肝硬化患者组PON活性为(153.78±107.54)U/ml,两组差异有显著性(P<0.01)。结论本方法测定血清中PON的活性操作简便、精密度、线性良好。肝硬化患者血清PON活性与正常人组比较差异有显著性。

Objective To establish a method for determining the serum activity of paraoxonase(PON) and to investigate the PON activity in normal subjects and patients with liver cirrhosis. Methods PON activity was measured spectrophotometrically at 270 nm with phenylacetate as substrate, and calculated through increased absorbance rate of the product p-phenol. Results The optimal conditions of test reaction were pH 8.0,substrate concentration 10 (mmol/L) and calcium concentration 2 mmol/L. The coefficient of variation (CV) within batch was (4.3%) and CV between batch was 5.0%. The average value of serum PON activity was (284.95±83.76) U/ml in normal group and (153.78±(107.54)) U/ml in the patients with liver cirrhosis. Conclusions The test method is easy. Precise and linearity are fine. PON activities reduce significantly in the patients with liver cirrhosis.