连续监测法测定血清丙氨酸氨基肽酶

A kinetic method for alanine aminopeptidase in serum

目的 建立血清丙氨酸氨基肽酶 (AAP)连续监测法。方法 以丙氨酰对硝基苯胺 (Ala pNA)为底物 ,研究AAP作用于此底物的动力学特征 ,选择最适反应条件 ,建立血清AAP测定速率法及参考值 ,同时观测肝胆疾病患者血清AAP作用于此底物的动力学特征 ,选择最适反应条件 ,建立血清AAP测定速率法及参考值 ,同时观测肝胆疾病患者血清AAP水平。结果 酶反应最适pH8 0 ,Tris HCl缓冲液的最佳浓度 15 0mmol/L ,Ala pNa浓度以 3mmol/L为宜 ,米氏常数 (Km) 0 74mmol/L ,在 8min观测时间内吸光度变化与时间成比例 ,线性范围可达 180 0U/L ,平均批内、批间CV分别为 1 0 4%和 2 0 2 %。 2 0mmol/L甘油三酯、2g/L血红蛋白、340 μmol/L胆红素对酶活力测定无干扰 ,正常成年人群参考范围 ( x± 2s) 4 1～ 77U/L。肝胆疾病组血清AAP明显高于健康对照组。结论 血清AAP活力是鉴别诊断肝胆疾病的一项特异、灵敏的指标 ;连续监测法适用于各种类型的自动化分析仪 。

Objective To establish kinetic assay method for alanine aminopeptidase(AAP)in serum,be applied to clinical diagnosis primarily.Methods The kinetic property of AAP was studied with Ala pNA as substrate.It was optimized to the assay of serum AAP,and established the kinetic assay method and reference limits.Were determined AAP activity in serum of hepatobiliary disease subjects In the meantime.Results Optimum pH of assay for serum AAP was 8.0,concentration of Tris HCl buffer was 150 mmol/L,the final concentration of Ala pNA was 3 mmol/L.Michel Meten constant(Km)was 0.74 mmol/L.Absorbency increased along with time in 8 minutes at least.The linear limit extended to 1800 U/L.The withn run CV and among run CV was 1.04% and 2.02% respectively.The concentration of TG up to 20 mmol/L had noninterference to reaction,so did Hb up to 2g/L and T Bil up to 340 μmol/L.Reference limits for AAP in adults( ±2 s ) was 41～77 U/L.AAP values in serum was significantly higher for hepatobilary disease subjects than for healthy subjects.Conclusions: AAP in serum is a very specific and sensitive indicator of hepatobiliary disease.