Kouzuma T, Takahashi M, Endoh T, Kaneko R, Ura N, Shimamoto K, Watanabe N
Diagnostics R&D Department, Fine Chemicals and Diagnostics Division, ASAHI KASEI Corporation, 632-1, Mifuku, Ohito-cho, Tagata-gun, 410-2321, Shizuoka, Japan.
Clin Chim Acta. 2001 Oct;312(1-2):143-51. doi: 10.1016/s0009-8981(01)00614-3.
A sensitive and simple enzymatic cycling method is described for the quantitation of myo-inositol in biological samples.
The method involves the use of a sensitive and simple enzymatic cycling method is described for the quantitation of myo-inositol in biological samples. The method involves use of thio-NAD(+), NADH and thermostable myo-inositol dehydrogenase (IDH; EC. 1.1.1.18) and measurement of the increase in absorbance at 405 nm of thio-NADH at 37 degrees C.
The calibration curve for myo-inositol was linear (r=1.00) between 10 and 400 micromol/l. Analytical recoveries of exogenous myo-inositol added to serum and urine were 100-105% and 98-103%, respectively. Within-run and between-run coefficient of variation (CV) were 0.6-2.1% and 1.1-3.0%, respectively. This method was free from interference by hemoglobin, bilirubin, ascorbate, chyle, various sugars, sugar alcohol and myo-inositol phosphates. With the use of myo-inositol as a standard solution, the serum myo-inositol concentration (mean+/-SD) was significantly greater in patients with diabetes mellitus (DM) without nephropathy (73.0+/-13.8 micromol/l, n=7) than in healthy individuals without DM (61.0+/-12.4 micromol/l, n=20). The urinary myo-inositol concentration was also significantly greater in patients with DM without nephropathy (793.3+/-870.3 micromol/l, n=7) than in healthy individuals without DM (76.0+/-63.0 micromol/l, n=13).
This new method is simple, sensitive and enables quantitative analysis of myo-inositol.
描述了一种灵敏且简便的酶循环法用于定量生物样品中的肌醇。
该方法采用一种灵敏且简便的酶循环法用于定量生物样品中的肌醇。此方法使用硫代-NAD(+)、NADH和耐热肌醇脱氢酶（IDH；EC. 1.1.1.18），并在37℃下测量硫代-NADH在405nm处吸光度的增加。
肌醇的校准曲线在10至400微摩尔/升之间呈线性（r = 1.00）。添加到血清和尿液中的外源性肌醇的分析回收率分别为100 - 105%和98 - 103%。批内和批间变异系数（CV）分别为0.6 - 2.1%和1.1 - 3.0%。该方法不受血红蛋白、胆红素、抗坏血酸盐、乳糜、各种糖类、糖醇和肌醇磷酸盐的干扰。以肌醇作为标准溶液，无肾病的糖尿病（DM）患者的血清肌醇浓度（平均值±标准差）（73.0±13.8微摩尔/升，n = 7）显著高于无DM的健康个体（61.0±12.4微摩尔/升，n = 20）。无肾病的DM患者的尿肌醇浓度（793.3±870.3微摩尔/升，n = 7）也显著高于无DM的健康个体（76.0±63.0微摩尔/升，n = 13）。
这种新方法简便、灵敏，能够对肌醇进行定量分析。
