Fluorometry of citrate in serum, with use of citrate (pro-3S)-lyase.
Fluorometry of citrate in serum, with use of citrate (pro-3S)-lyase.
复制标题
使用柠檬酸 (pro-3S)-裂解酶对血清中的柠檬酸进行荧光测定。
作者：
A. Tomisek;E. Winkler;S. Natelson
我们描述了人血清中柠檬酸盐的酶测定程序。用柠檬酸草酰乙酸裂解酶将柠檬酸盐降解为乙酸和草酰乙酸（pro-3S-CH2-COO-产生乙酸）（EC 4.1.3.6）。一些草酰乙酸失去二氧化碳形成丙酮酸。添加苹果酸和乳酸脱氢酶（EC 1.1.1.37 和 1.1.1.27）可以测定生成的草酰乙酸和丙酮酸，从而测定柠檬酸盐浓度。通过荧光测定法测量 NADH 浓度的降低。将通过该程序获得的 30 个连续人类血清的结果与柠檬酸盐转化为五溴丙酮的程序进行比较。两种程序获得的值没有统计学上的显着差异。通过该程序发现的 25 名献血者血清的值范围（平均值加或减 2 SD）为 12.8-27.2 毫克/升（平均值为 19.0 毫克/升）。在葡萄糖耐量试验期间通过两种方法测量的血清柠檬酸盐在施用葡萄糖（和内源性胰岛素）的影响下从初始值下降。在这些葡萄糖耐量测试期间还测量了胰岛素浓度。葡萄糖和胰岛素浓度恢复至初始值后，柠檬酸盐浓度仍低于正常值。这与已发表的报告相符。
We describe a procedure for enzymatic assay of citrate in human serum. The citrate is degraded to acetate and oxaloacetate with citrate oxaloacetate-lyase (pro-3S-CH2-COO- yields acetate) (EC 4.1.3.6). Some oxaloacetate loses CO2 to form pyruvate. Addition of malate and lactate dehydrogenases (EC 1.1.1.37 and 1.1.1.27) permits determination of the oxaloacetate and pyruvate generated, and thus of the citrate concentration. The decrease in NADH concentration is measured fluorometrically. Results obtained for 30 consecutive human sera by this procedure were compared to the procedure in which the citrate is converted to pentabromoacetone. There was no statistically significant difference in values obtained by the two procedures. The range of values (mean plus or minus 2 SD) found for sera from 25 blood donors by this procedure was 12.8-27.2 mg/liter (mean, 19.0 mg/liter). Serum citrate as measured by both procedures during a glucose tolerance test was decreased from initial values under the influence of administered glucose (and endogenous insulin). Insulin concentrations were also measured during these glucose-tolerance tests. Citrate concentrations remain subnormal after the glucose and insulin concentrations return to their initial values. This accords with published reports.