血浆弹性蛋白酶的微量测定和临床应用

Microassay and clinical application of plasma elastase

目的 拟建立一种血浆弹性蛋白酶的快捷、微量测定方法。方法 以琥珀酰甘氨酰对硝基苯胺 (succinyl-L -trianalinyl-p -nitroanilide ,SLAPN)作为弹性蛋白酶的作用底物 ,根据单位时间内 4-硝基苯胺释放量 (A450nm)的变化 ,反应弹性蛋白酶的活性。结果 线性范围为 0～ 5 0 0 μg/L,批内和批间误差分别为 5 .0 2 %和 8.3 2 % ,血浆用量仅为 2 0～ 40 μl。正常健康人 (n =12 )血浆弹性蛋白酶含量 (3 7.5 0± 15 .5 6)μg/L。肠瘘合并感染患者 (n =6)为 (4 8.40± 2 7.82 )μg/L,明显高于正常人 (P <0 .0 1)。猪急性出血坏死性胰腺炎 (5 %牛磺胆酸钠 + 80 0 0～ 10 0 0 0u/ml胰蛋白酶 )诱导12h后为 (2 3 9.0 6± 180 .2 4) μg/L明显高于诱导前水平〔(3 6.15± 9.40 ) μg/L,P <0 .0 1〕。结论 该方法操作简便、快捷、灵敏度高、特异性好 。

Objective To develop a simple spectrocolorimetric method to measure human or animal elastase activities in plasma. Methods Human or animal elastase activities in plasma were determined by the amount of 4-nitroaniline released per unit time, measured by the absorbance at 405 nm, with succinyl-L-trianalinyl-p-nitroanilide as substrate. Results The linear range is 0～500 μg/L. The intra-and inter-assay CV was 5.02 % and 8.23 %, respectively. The amount of plasma dosage required was no more than 20～40 μl. Plasma samples from 12 healthy adults and 6 patients with intestinal fistula and infection were measured by this method. The plasma elastase activities were (37.50±15.56)μg/L and (48.40±27.82)μg/L, respectively( P <0.05). Plasma elastase activities before and after actute hemorrhagic necrotizing pancreatitis in pigs were (36.15±9.40)μg/L and (239.06± 180.24 )μg/L, respectively ( P <0.01).Conclusion The method is simple, rapid, precise and cost effective. It can be used routinely in the clinical practice.