血清镁离子的丙酮酸激酶法测定

A New Enzymatic Determination of Magnesium Concentration in Serum by Pyruvate Kinase

目的:建立经济、准确、特异的酶法测定血清镁离子新技术。方法:根据Mg^(2+)为丙酮酸激酶(PK)激动剂的原理,偶联乳酸脱氢酶(LDH)反应测定Mg^(2+),并进行方法学研究。结果:该法与定值血清的相对误差为1.05%～2.50%,批内CV<2.02%,日间CV<3.12%,线性范围0.2～2.0mmol/L,回收率98.0%～102.8%。钾、氨、钙、锰、铜、锌、铁离子以及胆红素、甘油三酯和血红蛋白对镁离子测定无干扰。与原子吸收(AAS)法、二甲苯胺蓝(XLB)法和Calmagite(CAL)法的回归方程分别为:Y=0.999x-0.03(r=0.980)、Y=0.118+0.827x(r=0.933)和Y=0.982x-0.037(r=0.960),本法测定值与其它方法均无显著性差异。试剂复溶后(4℃)稳定至少5天。结论:建立的酶方法经济、准确,可在多种自动与半自动生化分析仪上应用。

Objective:To develop a new economical,accurate and specific method of enzymes to determine serum magnesium con-centration. Methods: According to the principle that pyruvate kinase(PK)is activated by magnesium ion,Mg2+ concentration was measured by PK coupling a system of lactate dehydrogenase and the studies of methodology were performed. Results: The relative error rates between results of proposed method and ones from BM serum of quality control were from 1.05 % to 2.50% .The mean imprecisions of within-run and day to day were less than 2.02%and 3.12% separately. The linearity ranges of the method were from 0.2 to 2.0 mmol/L; the recoveries were from 98.0% to 102.8%. Aqueous solutions of K+ ,NH_4^+,Ca2+ ,Mn2+ ,Cu2+ ,Zn2+ and Fe3+ were tested with no significant interference,and no interference from biliru-bin, triglyceride and hemoglobin was observed. The regressive equations of the proposed method versus AAS,XLB and CAL were respectively Y=0.999X -0.03(γ =0.980),Y = 0.118±0.827X(γ =0.933)and Y = 0.982X - 0.037(γ = 0.960).There were no significant differences between the results from proposed method and ones from other methods. Working reagents were stable for at least 5 days at 4℃. Conclusion: The enzymatic method developed with economy and ac-curacy can be used to measure Mg2+ concentration in serum by various automatic or semi-automatic analyzers.