尿中蓚酸測定キット(Sigma社)の有用性

Abstract

蓚酸酸化酵素を利用した蓚酸測定キット(Sigma社)の有用性につき検討した.1)本法における添加蓚酸の回収率は66.8%～113.2%, 平均110.6%であった.2)再現性は, within assayでは1.5～5.0%, between assayでは4.0～11.6%であった.3) modified Hodgkinson and Williams法およびion chromatography法とよく相関しそれぞれの相関係数は0.833, 0.796であった.4)健常男子の蓚酸排泄量は8.6～54.5 mg/dayで平均21.8 mg/day (SD:14.1 mg/day)であった

Many methods for measuring urinary oxalate have been reported. However, most of them are unsuitable for clinical use because of complexity and difficulty. We tested the value of the Sigma kit for measuring urinary oxalate. In principle, after extraction from urine, oxalate is oxidized to hydrogen peroxide in the presence of oxalate oxidase and the hydrogen peroxide reacts with 3-methyl-2 benzothiozolinone hydrazone and 3-(dimethylamino) benzoic acid in the presence of peroxidase to yield an indamine dye with a maximum absorbance at 590 nm. The linearity of the standard curve and reproducibility of this method were measured and good results were obtained. (Linearity: r = 0.998, within assay: C.V. = 1.5 to 5.0%, between assays: C.V. = 4.0 to 11.6%). The correlation between this method and modified Hodgkinson and Williams' method or ion chromatographic method were 0.922 and 0.796, respectively. The overestimation effect of added ascorbic acid was completely inhibited by FeCl3 which had been added beforehand.